The ticket machines on bus are being upgraded to read PlusBus e and m tickets. Ticketer (largest supplier) can scan the aztec code on bus, but is in the process of writing a fix so that it correctly reads the NLC code. Stagecoach, as mentioned, currently has barcode readers on limited services and is not ready for these to be included in the W Yorks trial.
There is a known issue with NFC clash in Ticketer machines where the barcode scanner and NFC reader are close together, so trying to scan a barcode can trigger the NFC reader (its faster than the barcde scanner) to open the wallet and, and then make a TOTO payment where the customer has given permissions.
Bus companies get around the clash by only allowing their barcode products in app, and suppressing the NFC reader in the device, which is relatively straightforward (a couple of lines of code and permission from Google/Apple/Samsung, which is simpler and quicker than you might expect)