(Indeed, to date it doesn't seem possible to open the NFC function on a Mainland UnionPay card if the account was opened with a passport. Those with different experience please post.)
You mean tapping a card like PayPass? It works for me on my Chinese HSBC UnionPay credit card. The same card also works via Apple Pay.
Of course I'm pretty sure a foreign issued UnionPay card won't work with Apple Pay as the Apple Pay website clearly lists the supported financial institutions and they are all on the mainland.