There was something similar in the last Cruise.co brochure that I received .... comparing Past passenger benefits,tipping,kids clubs,drinks and a general ship guide; but I haven't seen it on thie website.
After a lot of searching I have found the information you are after. I always go onto in.cruise.co however the interesting thing is that there is a very similar site which is www.cruises.co.uk (note the extra 's' in cruise). It all belongs to the same group but on the right of the Home Page under Berlitz Ratings there is a section - Cruise Info - with a sub section Drinks Info. It also details laundry facilities, fuel supplements, weddings at sea - in fact many of the issues people constantly raise questions about. Very strange!! I think I'll use that site in future as the same questions are all listed there but the format seems a bit easier on the eye.
Look on www.cruises.co.uk (which is basically the same site as this). The info you require is bottom right under Cruise Info.