I don't think he meant "reward" as material, but that he had earned Jesse's trust. Like, ...

I thought it was pretty obvious. Idk how you can read it as a material reward after all we've seen. His reward is to be indespensable to Jesse. Whether that means gaing his trust or holding a dangerous secret hostage we don't know. Law is a little crazy after investing all he has in Jesse. Feelings, dignity, his freedom, his future, all poured into Jesse. He wants...no he needs to have his "investments" returned. With devidens.