Probably, you missed the part where you need unique id’s if you want to use it within a repeating group:
If you create unique IDs for the elements within repeating group, it will work for each cell. See the demo:
You can set unique IDs for any element like this:
And then, you can set them in your air tooltip in a cell:
Here is the editor if you want to check more: Tests for Forum 9 | Bubble Editor