I wondered if there was any clarification on how the bonus action uses of Melf’s Minute Meteors are supposed to work. 
The part in question reads as follows: “When you cast the spell — and as a bonus action on each of your turns thereafter…” as I understand this, it lets you use two meteors (4d6) as an action when you cast this spell and two meteors (4d6) as a bonus action on the same turn, leaving you with another two meteors to use on your next turn or over a few turns afterwards. 
By this ruling it does an equivalent amount of damage to Fireball on the first turn and you could do half as much again on your next turn, at the expense of a smaller area (arguably better since your less likely to hit your party members) and uses an action and two bonus actions. 
I want to know if this is how it’s supposed to work or if they got the wording wrong in publishing since similar spells are clearer on when the can be used, such as:

Crown of Stars - “You can use a bonus action to send one of the motes streaking toward one creature or object within 120 feet of you.”

Arcane/Bigby’s Hand - “When you cast the spell and as a bonus action on your subsequent turns…”

Both of these spells are clear on when you use your bonus action to affect the spell, but Melf’s Minute Meteors is unclear at best or just a better Fireball at worst. If this is the way it’s meant to work, is it worth it taking up extra actions and targeting a smaller area to be arguably better that Fireball, a spell that’s been admitted to be overpowered for its level?

The part in question reads as follows: “When you cast the spell — and as a bonus action on each of your turns thereafter…”

Don't really see what's confusing about this. The turn you cast is on is not a turn "thereafter." If it just said thereafter then it would be confusing, but adding "turns" in there clears it up.

That’s just the messed up English language for you.

“as a bonus action on each of your turns thereafter” = “as a bonus action on your subsequent turns”

Those are just two different ways to say the exact same thing.

Quote from scatterbraind >>

The part in question reads as follows: “When you cast the spell — and as a bonus action on each of your turns thereafter…”

Don't really see what's confusing about this. The turn you cast is on is not a turn "thereafter." If it just said thereafter then it would be confusing, but adding "turns" in there clears it up.

 This. 

Round 1 cast the spell and fling two meteors. 
Round 2 as a bonus action fling two more 
Round 3 same as round 2

Or I gues you could do one at a time, I believe the spell says one or two meteors per attack 

The confusing part comes from the different phrasing for similar effects, if they’re supposed to perform in the same way. The phrasing “…on each of your turns thereafter…” could be interpreted as being on the turn after the one you cast this spell with, or it could be ‘thereafter’ the action used to send out the meteor(s), it’s still your turn after casting the spell so you could use a bonus action to fire more meteors. 
Arguably it’ll be up to your DM on how they want to run the spell. 

No arguments from me that English can be confusing. 

I tend to rule it this way, you can use your bonus action following the action used to cast the spell. So the first round you can hurl up to 4 meteors. I don't see it as making it OP in anyway.

It's just that having it be able to do this much potential damage with it puts it at the same level as fireball, a spell made to be overpowered by the designers admission. Then you get subsequent turns to deal even more damage with it. It does take up an action and bonus action though, so I guess it's fine to just leave it up to DM's interpretation on weather that balances it out or not.

P.S. Thanks for replying to a post I made almost half a year ago. I've managed to get a bit more experience in running my games now, but still love discussions where people talk about the different ways they run their games. I feel it helps me to improve the experience at my own table.

Consider this though, Most battles do not last more than 3-4 rounds of combat. So by the time you ramp up to the amount of extra damage the meteor allows the fight is over. Also fireball has a great amount of damage AND area of effect. This allows for large swathes of enemies to be taken out. Meteors does not have this. A few large sized monsters are effectively a single target to such a spell. Also when designing a spell you have to look to existing spells as examples. Even IF fireball was always meant to be OP it is allowed in the game and sets a precedent for third level spells and their power scale.

Quote from scatterbraind >>

The part in question reads as follows: “When you cast the spell — and as a bonus action on each of your turns thereafter…”

Don't really see what's confusing about this. The turn you cast is on is not a turn "thereafter." If it just said thereafter then it would be confusing, but adding "turns" in there clears it up.

You're proposing that 'thereafter' refers to subsequent turns, but the hyphenated premise doesn't mention anything about subsequent turns. "Each of your turns thereafter" is the same as saying "Each of your turns after <condition>." After what condition? We return to the spell-casting prior to the hyphen, which is why the hyphen exists. As such, "after you cast the spell, on each of your turns, you can use a bonus action to."

Nothing in this premise precludes the round you cast the spell, unless you already used your bonus action for something else.

As an aside; comparing this to a fireball seems a bit inaccurate- fireball takes an action, not an action, concentration, and multiple bonus actions. Moonbeam would be a better metric, and in the same slot, moonbeam is far and away the winner by all damage metrics.

Yes thereafter refers to the turns after the turn you cast the spell on. There after and after that are equivalent so on the turn you cast - and on the turns after that is an equivalent statement. Phrased that way it’s clear: 0, 1 or 2 meteors per turn until you run out of meteors. Because of the 10 minute concentration period it’s quite possible to use the same spell in 2 different small combats within a 10 min period. Center the meteor bursting in the middle of a hallway swarming with goblins and just behind the first set of goblins and you may well kill all 4-8 goblins in that section of the hall. If you need more damage throw 2 meteors to the same spot.

Quote from Wi1dBi11 >>

Yes thereafter refers to the turns after the turn you cast the spell on.

 English being a funny language, thereafter could also mean that after the action you use to cast the spell, you can use your bonus action on each of your turns to throw meteors.  While throwing 4 on the first turn does put it on par with fireball for raw damage, it has a significantly smaller area of effect. 

At some tables that difference won't matter and allowing it to be front loaded would make fireball obsolete while not allowing it will cause the spells to get used situationally.  In the group I play with, front loading the damage causes both spells to get used relatively frequently.  I think the decision on which way it works should be more about what causes both spells to get used than about trying to figure out what the designers intended.

Strictly speaking, the language is that you have to wait until your next turn. It says on each of of your turns thereafter. Your current turn isn't after you cast your spell. If they wanted to say that you could use your BA on that turn as well, then they could just drop the bit about turns - just say "After casting the spell for the duration, you may use your Bonus Action to...".

That said, I wouldn't be bothered if the DM allowed it to be frontloaded. The comparison to Fireball doesn't make it equivalent - to get that damage, you have to maintain concentration for two turns, the range is massively smaller, it gives the enemies chance to scatter (so AoE is further diminished) and it's taking much more action economy (although it's arguable that BA means very little to many casters). It's debatably better for single targets, but then there are other better spells for those too.