Card Present Retail - No, you only need an EMV enabled terminal and a merchant account on the Vital platform. 

Card Not Present - Yes, you must have an iOS application that has been developed for and on the Apple platform and uses in-app purchases. It must also be an iOS 8 app in order to work on the new iPhone 6 and iPhone 6 Plus.

E-Commerce - Apple Pay does not yet support payment options outside of card present or in app purchases.