Hi, 

I have created an item called - Bindings of the Monk - to give +1 to AC when unarmoured and +1 to unarmed strikes. 

I have put on the item 3 modifiers - 

Bonus - Unarmored Armor Class 1 
Bonus - Unarmed Attacks 1 Edit 
Damage - Unarmed Attacks 1

But on within the character the item is also showing as a Bonus Action, what have I do to do that? 

Are you talking about:

That is how my item looks, 

when I add it to a character it adds the modifiers as directed, shows up on the items.

It also shows as a Bonus Action. I can not seem to insert an image so it looks like this - 

 ANd I do not understand why? 

Hello Libsteve, could you please link the affected character?

What is your base item type and magic item type? Is it item and wondrous item or something else. My test item looks like this:
(FYI, for images, I am just taking a screenshot and uploading to imgur then using the insert/edit image button with a link to it)