I've briefly looked at this and the changes seem pretty minor. They're clearly looking to upsell pax to The Works as a revenue move.
Earn calculations are still a mess TT with no real relationship between spend and earn. You can have very small differences in fare prices (only a few $) that bump you do a different booking class which will change earn quite sifnificantly.
I've just looked at two upcoming trips I've booked which were both cheap fares.
WLG-BNE was $362 r/t ($162 fare and $200 tax) for a total of 7 SP over and 8 SP back.
WLG-SYD was $361 r/t ($168 fare and $193 tax) for a total of 15 SP over and 8 SP back.