You don't even need 2 bills. 1 bill and ask them to split it between 2 credit cards. I've done this many times with girlfriends (even in non i-dine places!). It's easier on the waiter/waitress than keeping 2 tabs going. Just ask them to split the bill 50/50. No problem with i-dine thinking that it's a duplicate charge if it's going on 2 different cards.