I recently created a bounty on a question, that I feel did not get an adequate answer. There were a couple of attempts (and I appreciate the effort). However it wasn't adequately answered. The bounty timeline ended, yet the bounty (350) wasn't returned. I see that if an answer receives 2 or more vote, but is not an appropriate answer, half is given, in this case, none received enough votes to make that happen? Link to question Help with Geocoding and Openlayers missing markers
As reported in the FAQ:
If you do not award your bounty within 7 days, the highest voted answer created after the bounty started with at least 2 upvotes will be awarded half the bounty amount.
In any case, you will always give up the amount of reputation specified in the bounty, so if you start a bounty, be sure to follow up and award your bounty to the best answer!
Who offers a bounty doesn't get back the reputation offered for the bounty, even in the case he didn't select any question to which give the bounty.