When using Apple Pay, Apple obviously stores your payment methods and for some cards, the Wallet app stores your transaction history. However, the Apple privacy policy for Apple Pay says they only use anonymized transaction history for their analytics.
But there is also Apple Cash. Apple Cash's privacy policy says that they do collect non-anonymized information on your transactions (and communication history from messages, email, and calls!), but they promise to only use it if they deem it necessary [1]. Take that as you will.
>To assist Apple Payments Inc. in preventing fraud when you are using Apple Cash to send, request, and receive money, Apple Inc. may provide it with approximate use patterns from your device about how frequently you communicate with that person by phone, email, or in Messages. No content of your communication is collected. This information is stored for a limited time, and in such a way that it is not linked to you unless the transaction with which it is associated is determined to require further analysis due to suspicious activity.
Again, I do trust Apple more than I trust FB to only use it when necessary... but they are still collecting it.