A thin blooded Vampire cannot create a blood bond at all, and ghouls are humans who are blood bound to a vampire. I would have to say that the ghoul would be an incredibly weak ghoul, (if it were to happen) and even if the ghoul were created, then that ghoul would not be blood bound to it's domitor, creating a very dangerous situation fro the Domitor of said ghoul, as they normally ghoul to maintain a loyal contigent of servants to have their wants felt and heard during the day. Just a thought.