I personally myself wouldn't trust Apple right now with this. It's something that is new and we know that anything involving credit cards and banks usually ends up in your privacy not being so private anymore. At least with bitcoin I can keep my privacy if I wish to. I see there being a lot of problems from the start anyway until they get everything ironed out.
The BSA actually makes it illegal to share details of banking transactions without permission of the account holder (unless there is a court order). Anyone engaging in banking services also much take certain security steps to keep information regarding transactions secure.
You would also have little issues with having your money stolen because cardholders are only liable up to $50 in the event of unauthorized transactions.