You need to post a link to the pattern you uploaded in the bounty thread, and the one whom placed the bounty will have to accept your reply to the post as "Best Answer". The reward then automatically transfers to you.
Have you spoken to the person since you say they seemingly can not get the pattern? What message are they receiving?
If the person responsible for the bounty does not set your reply as Best Anseer, you can post links to the bounty and to your pattern in this thread: