If Ainge is still looking for a backup forward, I think George would be the best pick available. His shooting is streaky, but teams still need to cover him; he'd provide more spacing than anyone in our bench except House. His defense is still solid enough; he could guard the taller 3s that will give problems to Tony Allen and mobile PFs fairly well.
Personally, I don't see much use to Bonzi. If we sign him, why did we keep Tony Allen? They're basically the same player - Bonzi is a better ball-handler, Allen is a better teammate.