The big question that hasn't been answered yet is will the iphone transmit and receive via the USB port? I don't claim to be an expert on high end phones, (heck all I have is a freebie Verizon phone) but if they can't send and receive on the USB port it's not possible to connect a Castle product.
Because the Castle link has to read the controllers settings when you first connect it, the USB port has to be capable of receiving. To update the settings to the controller the USB port has to be capable of transmitting. So if it can't do both, unfortunately it's an impossible feat. If it can, then there is a chance and I'd love to see someone try!
Thomas Porfert
Castle Tech Support