Well they do hide it a bit. It's on page 92, right by the seam, under the headline "Raise A Glass", which is possibly too stylistic for non native English speakers, who may be looking for something like "Drinks on your flight". This shows the domestic/Eurotraveller/World traveller drinks, but other drinks may be available in the forward cabin(s).
Anyway, since I've got the page open, this is what it says (stuff in parenthesis is my addition):
Originally Posted by Highlife Magazine
We're pleased to offer you complimentary alcoholic and nonalcoholic drinks from the onboard bar, including:
- Still and sparkling mineral water (generally Highland Spring, can be other brands on the return to London eg Ozarka or Arrowhead from USA/Canada)
- Orange, apple and tomato juice (concentrate from the Sunpride brand)
- Coca-Cola, Diet Coke, Sprite, Canada Dry, Schweppes Indian Tonic Water (Mini tins. Fevertree tonic is now available in the premium cabins, but it sometimes ends up on the trolley).
- Red and white wine (you may also get rosé).
- Heineken, Tiger and Amstel light beer (also a few London Pride).
- Gordon's gin, Smirnoff vodka, Johnnie Walker whisky, Glenlivet malt whisky, Otard cognac. (Also Jack Daniels whiskey, and Bacardi white rum).