I feel funny asking this question as I only fly First Class on British Airways and don't drink
Know it is free in First. I have no idea about the Club World policy.
I assumed it absolutely would be
Having said that my friends recently booked a flight from California to London and emailed BA Customers service and was informed only in the lounge prior to boarding
One must pay in Club World once on board for any Alcoholic beverages including wine or champagne

My thought was someone must be mistaken.
I greatly appreciate the correct answer
Thank You!