When you say "pitch bending," I'm guessing that you mean the kind of pitch change that occurs when you speed up or slow down a recording from its normal speed (that is, the speed that it was recorded at).
In the digital realm this effect is the result of playing back an audio stream at a different sampling rate than it was recorded at.
The usual meaning of "pitch bend," however, is in playing an instrument like a guitar where the pitch can be changed in mid-note by the player. And when you say "sounds do tend to register louder in the VU meters when I bend up 12 semitones," it sounds like that is what you are talking about. To make things even muddier, you seem to be equating loudness with the number of bits representing the signal. More bits means more, finer-graded steps between quietest and loudest, but loudest is still loudest.
All in all, I'm still not sure what it is that you are really asking. Maybe you can rephrase your question?