I doubt Bonnie could "un-compel" him, but it'd've been exciting to watch them come up with a way to save Jeremy from her. (Give Damon the side-eye-of-aneurysm until he agreed to undo it? Get Klaus to do it? Just tell him and see what happens (presumably it'd be futile, he'd been compelled not just to forget but also to go to Denver, which, come to think of it, that'd be *really* interesting as a metaphor for conditioning)?)