Yes, the two terminals are connected, but it's a bit of a walk. I haven't tried entering through terminal B to walk to terminal A though; I've only walked the length of entire airport by entering through my ticketed terminal. I imagine the TDC doesn't care as long as the departing city on the boarding pass says "San Jose"

For time consideration:
Elite A security line + Opt-out << General (or even elite) B security line + B security (opt-out potential) + walk to terminal A