Bounties are only revoked in exceptional circumstances. As mentioned by the MSE answer linked by David "I made a mistake" is a problem but by no means exceptional.
We also cannot prove one way or another that you did actually make a mistake and posted a bounty on the wrong question. It is up to you to be sure you are in the right place before making the ...
After the next build, the ban message on your flag summary page will indicate how long you must wait before flagging again:
Fair warning: flag ban durations are calculated on demand. If more flags are declined after you view this message, the duration may be extended; if more flags are marked helpful, the ban may be lifted entirely. You should treat ...
Maybe let the moderator know that the flag was for a previous version of the answer.
As I mentioned here, the new moderator flag dashboard shows an [edited] label if the post has been edited after the flag has been cast:
Duplicate questions are not deleted, they remain on the site as "signposts" to the existing answer that might be found by a Google search that doesn't find the duplicate question.
If you realise that one of your questions is a duplicate, it is a good idea to flag it as such.
In addition to above explanation by Blackwood, your question might already have fetched some comments or answers by others, so your question page now has their contribution also.
Thus, it would not be ethical of you to deny them the credit for their part of contribution by summarily deleting the question.
Thus, it is always better to have a second/ third ...