I sometimes feel the need to reward the asker for posting a very useful and thoughtful question. Bounties are rewarded for answers, and not for questions. I can only upvote the question once, but if I'm ready to spare rep, is there any way I can reward the asker?
At present working of bounty, no there is not.
The bounty can be awarded only to answer.
To award the bounty to the OP, ask him to make an answer and then award it for the answer. Anyway I am not supporting this because, only to get bounty, if the OP answered his own question in which there is already an answer exists, if it is a plagiarism, it may subject to mod's actions.