https://www.cathaypacific.com/cx/en_...rd-linked.html

So instead of presenting a QR code for miles accrual and a card/mobile pay for payment, just tap a pre-registered card, and perform miles accrual and payment with the tap.

Only 16 partners are listed to be currently supporting this (see above link)

(I suspect) Mobile pay cannot do this - they can't link DAN numbers to Cathay membership numbers.