I can't speak for Cloud 9, but for Y, it appears they do catering in the departure city and the quality will vary. The whatever-it-was I got from Zanzibar is perhaps the worst I've had in the air ever.

The ethiopian wines I've had, in Ethiopia - not on board - are quite sweet. Pairs very well with spicy food (should work fine with most injera) and cheese.. but maybe not with desserts. In general, I'd try and sample them on board. As for the ethiopian food, it's like medium Indian on the chilli, but very rich in flavour. Considering that your senses of taste and smell are dulled in the air, I can hardly think of anything more suitable to eat up there (and down here for that matter).