No, they are different amps, although BIAS FX integrates the amps from BIAS Amp if you own it as well. BIAS FX has a different/new sound engine, and if you use an amp from BA in BFX, and compare it, it sounds better in BFX (without any effects, just straight amp and cab), although what sounds better is subjective, and that's not to say BA sounds bad by any means, it sounds awesome to me. BFX has the benefit of all the effects as well obviously, and the effects are pretty sweet.
If you try it out, make sure you have a good look around, also don't just load it up on a mono track, take advantage of the stereo stuff and dual amp paths etc, in the options there is a mono to stereo setting with 3 options, disable, left and right. For stereo/dual amp paths try disabling that, it sounds really sweet for dual amp path/stereo effects.
It may or may not be your thing, or to your liking, but only one way to find out. I never really looked back after trying BA when it came out, and then BFX, 99% of the time it's either of those or TH2, sometimes another amp sim just suits and nothing else works better in that situation, but that's not offten.