There is at least 3 versions on the Android Market website: Angry Birds, Angry Birds Rio and Angry Birds Seasons. All are compatible with the Thunderbolt. I have the main one (Angry Birds) installed on my Thunderbolt. Use this website to get to the Android Marketplace:
As others have said, there are 3 version of Angry birds out. The free versions are ad supported or you can get the paid version that is ad free.
All three versions work on the Thunderbolt just fine...I have the 3 stars on all levels to prove it (well at least on Rio, I do, LOL).