the thing is, it really doesn't come to 'what program' do you learn. not yet, anyway. first practice the theory. modeling, texturing, lighting, rendering... all those are pretty consistent from platform to platform, but if you can do those things well, it doesn't matter which program you use, cause the only real difference is lingo and interface.
i kinda see 3d as similar to music. you can learn to create music on a guitar. as you get better with the guitar, your music sounds better. afterwards, if you decide to switch to the piano or flute, all you really gotta do is understand how they work. after that, you pretty much understand how to play the music already.
Accept no substitutions.