Thanks to the information at the start of this thread, I've now booked a discounted domestic Chinese flight on Trip.com, for a flight operated by Air China. The question is, is it possible to "Manage my Booking" in the way that I'm used to with European airlines? I'm thinking seat selection, view baggage allowance, online check-in, that sort of thing. I can't see that visible on Trip.com, and I can't get my booking to appear on the Air China website.

Any suggestions?

You'll need the Air China PNR or e-ticket number. Once you have that and your family name, you should be able to log onto the Air China site and look at your booking.