Indeed, Avios — but not tier points — can be earned when flying a CZ marketed and operated flight. Eligible fare classes and the earning percentage for each are listed at the link supplied above by Y747 .

This similar to how Avios can be earned on other non-Oneworld partner airlines, such as LATAM.
See also:
https://www.flyertalk.com/forum/british-airways-executive-club/2124359-china-southern.html