The idea is that you accept the answer that is most helpful to you, but you can award your bounty to any answer (it makes sense to award it to one that is of value, obviously, but it is your bounty to do with what you will)
So I'd suggest in future you could do things the other way round, but in this instance I wouldn't worry about it.
Remember, rep is ...
The official recommendation for accepting answers is
Choose one answer that you believe is the best solution to your problem.
The accepted answer is the one that shows up at the top of the answer list for visitors. It's generally best to accept the answer that provides the best overview of the topic. The choice of accepted answer influences how all ...
There's a 24 hour wait period on awarding bounties after they have been offered. If you try to award it sooner, an error message will display notifying you that you can only award it after n hours, where n is 24 hours minus the number of hours that have elapsed since the bounty was offered.
There's no official name for this that I'd be aware of, so I'm ...
From StackOverflow help
To avoid overly promotional bounties, if you are offering a bounty on a question that you have already posted an answer to, your minimum spend is 100 reputation (not 50).
You don't have the reputation needed for 100 yet