Yup. The vending machine is some small company with after-market credit card readers installed, with NFC chip support.
As far as card selection, you just click the one you want to use which brings it into "full view" with a list of recent transactions. Then just hold it up to the NFC symbol and you'll see the TouchID Fingerprint option appear out of the blue. You then put your thumb to it and boom...the credit card reader clicked, read "**** TOKEN SENDING..", then said "Transaction approved. Please select option." Then selected the Diet Coke, and once the machine processed the transaction, it showed up almost immediately on my iPhone under "recent transactions" below the card.
This was on a Blue Cash Amex. I am not sure if all cards support recent transactions summary.