Hi Simon's Girl, welcome to Cruise-Chat.
Here is a link to their contract, see #5 for wine and corkage fee. You can also purchase wine on board for dinner or you can order it on-line. Actually, I think it's a pdf form that you can download. Their wines are $20/up for a bottle on board. They will cork it and serve it the next evening if you don't finish it. Most of the cabin stewards I have had will gladly open your wine for you and bring you ice (if needed) to chill it. Best wishes for your upcoming cruise, and once again, welcome aboard!