Kiwiflyer,

TG has a U class, which is 110% status and redeemable miles. U is for their E+ product, which is sold as a 4th class on its 345 and 346 jets.

SQ,

As you know, G,V,Q,N,T (think should be ranked in this order) are no miles classes. I believe the ranking for the the Y tickets would be in this order , based on my limited knowledge.
Y,S - full fare economy. think its 1 yr tix
B - 4 mth tix. ?full fare
E - 1 mth tix. discounted, with miles

I have not seen a G ticket in use, but have heard of an M fare originating BKK. But it ranks higher than E.

Not sure about the other classes.