From Apple:
When you make a purchase, Apple Pay uses a device-specific number and unique transaction code. So your card number is never stored on your device or our servers, and when you pay, your card numbers are never shared by Apple with merchants.
.... Apple Pay doesn?t keep transaction information that can be tied back to you. Your most recent purchases are kept in Wallet for your convenience, but that?s as far as it goes.
Source:
https://www.apple.com/apple-pay/#mn_p