How to render a taxonomy field in a Views' PHP code field?
I can't comment because of rep..
Use devel module and use the dpm() function in your php for some debugging, drill down and find the value you are looking for then double click the value in the debug widget and it should tell you your field value.

here's my guess:

$data-&gt;field_field_my_category[0]['raw']['value']; 

Might be slightly different if it's a tax term but devel is your best friend and you should use it quite frequently. Stop guessing and start debuging (best advice i've ever gotten).