It seems wine is OK to bring aboard with no problem, beer too, but you would definately have a problem with Whisky. You may be able to get it through by putting in your checked luggage, but wrapping it very well, its up to you.
I am not certain about Cunard which is owned by Carnival. On Carnival you should have no problem so maybe this holds on Cunard.
Some cruise lines like Holland American & Princess permit bringing wine aboard the ship strictly for consumption in your stateroom.
You should incur very little obstacle to carrying the wine aboard ship well padded in your checked luggage. We usually bring a supply aboard wrapping the bottles inside of plastic bags that are provided by our newspaper delivery service. I know the top. The purpose is to retain the wine and not soil clothing in the event of breakage. We have cruised since 1968 and never hasve be had a bottle break.