I have two wizards on my account. I would like to know if I can trade treasure cards between them.
No since you can't put TC's in the shared bank. The best way to get around this one is to create a free account and create a wizard just for TC trading if you don't have a totally trusted and I mean totally trusted, person to trade them to and then get them back for on the other wizard.
The only draw back I have seen in this is not all TC are trad-able so not all can be transferred around.
You cannot trade between wizards on the same account. You would have to trade them to a friend, then load your other wizard, and have your friend trade them back to you. Or buy a second account so you can do this all on your own.