Makes sense as only your issuing bank can decode the Device Unit Number to your credit card.
The merchant, processing network, or Visa/MC have no idea who the number belongs to. I'm assuming Dividend Dining ties in somehow with MC to pull transactions.
ApplePay 2.0 is supposed to include a rewards program so perhaps in the future this wouldn't be a issue.
Also as a side note ApplePay - it sends two numbers from the phone with each transaction - the Device Number and a one time token. The device number is the same with every transaction and the one time token is used by the bank to verify the transaction is valid.