I would say it completely depends on who's developing your film.

I shot an engagement session at dusk and asked the lab to push the film. One roll at 800, one at 1600, and one at 3200. I'm not even sure if the lab pushed the 800 roll or if they just faked it. The roll at 1600 was definitely pushed, but when compared to box speed, it was so different that I now question whether I'll ever desire to push color film again.

I say, push B&W all you want, but color needs to be exposed properly near box-speed in order to look right.