Only some airlines require you to present the credit card used, however if you book through a travel agent (including online travel agent) rather then the airline direct, then this isn't necessary at all, although the travel agent may want you to provide a photocopy of your passport and credit card.
Airlines also accept a photocopy of the card at checkin (except Etihad).
Another option, if you want to make life easy for yourself, request you credit company for a second card for your fiance/wife in her name. This is just assigned to your account, and book the card using this. I do this for my wife.
It's generally cheaper and easier to book tickets online from here. Use websites such as kayak, travelsupermarket etc to search.
