There are lots of very good reasons for the 200 point cap, but at the same time it adds an anticlimactic area above the 200 point cap each day.
Why not let the points over the 200 cap go into another counter that can only be used for bounties? It would encourage the use of bounties on some older questions which don't get much love, but which would be useful to have good answers to. All while keeping to the intention of the cap in the first place.
(This suggestion is from Vitaly Mijiritsky, but he's too lazy to post it :P)