Apparently China Rush is recruiting in the US:
JC Nashville @JCNashAuditions
John Casablanca Grads, casting season three of The Amazing Race: China Rush. Submit here: jcgrads.com/?b=4349
That link goes to a login page, so I expect you'd have to be a graduate of their training to get in for the details. They were posting this under many titles like JC Baltimore and JC Tulsa, so it sounds like they are trying to get the word out nationally.