Depp, Downey, and Pitt aren't only A listers because they have had multiple 100m movies, but they have also all received multiple academy award nominations, and have been around for decades to develop that sort of status.
While, I have no doubt that CT is a box office draw, he's still new to Hollywood. He's been around a few years. It remains to be seen if he'll become the next Depp or if he'll become the next Josh Harnett.