SkyTeam is one of the big three airlines alliances with the following members:
If you have Elite Status with one member then you can use priority check in, check extra bags, access lounges and board first with all members.
China Southern are offering to match pretty much any airline loyalty program, including other Sky Team members:
And looks like you’ll retain status until February 2019.
You need to sign up for a China Southern SkyPearl account if you don’t already have one. Part of the signup process involves a verification code sent to your mobile.
Then send an email to email@example.com with proof of your competing status. I just sent a screenshot of my BA account.
Good luck and maybe see you for a drink in a Sky Team lounge somewhere!