This'll probably come down to being one of the many 'good in theory' stunts. On a powered bike, it'd be so ludicrously difficult that anyone who's of sound mind would just give it a miss completely.
On a bicycle...it should be possible. But to get a backward stoppie going in the first place, you can't be going very fast. Also, when you lean into a bunny, you lose even more speed. Then you'd have to time the bump, which would be difficult with a reverse angle. Get all that right, and even then you'd be lucky to get 20ft...if anything.
I think it'd just be too much of a pain to do. Be nice to see once though.