The FAQ says it's 2 bottles per guest. (https://www.celebritycruises.com/faqs/all-faqs#before-you-board) And there's no corkage fee if you have the classic or premium beverage package. Both of those are not what I remember. Maybe they've changed recently?
What is Celebrity Cruises’ Alcohol Policy?
Celebrity Cruises® guests are expected to be responsible for their actions at all times, including during transfers to and from ships, inside terminals, while onboard, at our ports of call, during shore excursions and at our private destinations. Consuming alcohol to excess impairs one's judgment and reduces one's ability to recognize and avoid potentially dangerous situations. Guests who choose to consume alcohol must do so responsibly. The ship's staff may refuse to serve alcoholic beverages to any guest who does not consume alcohol responsibly, including those who have purchased an all-inclusive beverage package. Ship's personnel may request verification of a guest's age to verify they are of age to consume alcohol pursuant to this policy. Any guest that violates this alcohol policy will be considered for disciplinary action pursuant to the "Consequences Section" of this Guest Conduct Policy, and may lose their privileges to use areas or facilities of the ship.
Guests are not permitted to bring alcoholic beverages onboard; with the exception of embarkation day when each guests are permitted to bring onboard with them up to two (2) bottles of wine (which are subject to a corkage fee) per guests. A corkage fee does not apply to guests with the Classic Beverage Package or Premium Beverage Package. Security may inspect containers (including water bottles, soda bottles, mouthwash, canteens, etc.) at any time and will dispose of alcohol concealed in such containers. Alcoholic beverages that are purchased from onboard shops or in ports of call (which must be presented to security upon re-boarding), will be secured by ship's personnel. Alcohol secured by ship's personnel will be returned to guests just prior to the conclusion of their cruise vacation. Guests who are under the permitted drinking age will not have alcohol returned to them.