Hey Delta,
You have a discrepany on your partner mileage earning webpage. Under China Southern you have "Economy: Y, H, K, T, W, G" earning 100% base miles, 50% bonus miles but total miles earned is 100%. So either the total mileage earned should say 150% or you don't get the 50% bonus miles for those coach classes. If I had to take a wild guess I'm thinking there is no 50% bonus for those coach classes.
-RM