If you're booked in Y B H K M you're in b-flex. Other classes are b-light. C D J Z are b-business.
There is no curtain between classes, just different colours of head-rests.

In b-flex you'll get a fairly descent food: breakfast or salad/sandwich+desert, depending on the time of the day. Drinks are free (wine & beer included). Haven't seen a hot meal recently. They used to do it on flights over 2 hrs. B-business will get you an upgraded version of the meal, served on china, not plastic.

In b-light food and drinks are for purchase. Price and selection are reasonable (but it is my subjective assessment).

No service allowance for *G, as far as I know, but I am only FTL, so there is a chance that I haven't been exposed to some perks.