Hi Angus,
Welcome to FT, and to the Marco Polo Club!

From CX website:
https://www.cathaypacific.com/intl/f...112567,00.html

Please note that eligible Economy subclasses for mileage accrual with Qantas Airways will be revised from 31 October 2004.

So, if you travel in Economy Class, "V" will replace "S" as the new eligible subclass (however, if you travel with Qantas before 31 October 2004, you can still claim missing mileage in the "S" subclass within six months of your flight).

Summary of all Economy subclasses eligible for mileage accrual on or after 31 October 2004:
Economy Class (100%) -- Y
Discounted Economy Class (50%) – B, H, K, L, M, V

If you get miles, you get a tier point (or half a tier point in discounted).