I'm not sure how to Check the mileage on the China Southern site. I think it might not even say until you book it, but it's a short flight so it might just be the 500 mile minimum (they still do that, right?) ETA: found it - full earning is 450 miles, V class is 200, Z is 0.
You may have replied before my edit. Our points are with Delta, and it seems like Delta counts V class at 25% of mileage, but there is weirdness with Z. China Southern calls Z super discount and it earns nothing, but Delta calls Z business class and it earns 100% towards medallion. I'll have to check and see how close he is, but we have another visa run happening around Thanksgiving that will probably take us on Garuda Indonesia too, so there are other chances. I also care way more about him getting status than he does
Thanks!