If you're not a Chinese national, then you'll be treated just like any other low time foreigner after you get your CPL/IR which means pretty much zero chance of working for the Chinese national airline, let alone other Chinese carriers. Chinese airlines are in need of highly experience captains and that's why they're willing to recruit them from foreign countries and pay them top dollar, but not so newbie first officers. Local FO's in Chinese airlines usually go through a rigorous selection process to join as cadets where their training is conducted either locally or abroad. China Southern Airlines even have their own flight school in Western Australia and have been training their own cadets since the late 1990's at
China Southern West Australia Flying College.