You can look at their combination this way:
treat "China Mobile's mobile pay" as "Google Checkout" or "Paypal"
Their co-operation means
you can use "China Mobile's mobile pay" to pay for the .tel annual fee, withtheir platform.
Also, you can have a link in .tel domain, and link to China Mobile's platform to make other payments.
Didn't you think almost all domain Registrar can accept Paypal to make the payment, and you can put a link on you web to pay for the other fees?