After you beat them the tc gets sent to you automatically.
Keep in mind you won't get anything if it's already been claimed.
I don't know if this is still around, But adding on to what was said above.
If it's one of those "Decap (person's name) for 10k". Then you must save the replay and send it to the person who put the bounty. If this is still around/relevant to what you need.