Juice is available in the morning. The buffet area usually has iced tea and lemonade available throughout the day and you can always order iced tea in the dining room with your meal. Water is available 24/7 - of course you will have to purchase bottled water.
Yes, they do offer a wine package. There will be staff manning the wine display outside the buffet area on the day you board and you can purchase one of the various wine packages at that time. A copy of the Wine Package Menu can be found on the RC page of the CruiseReviews website ( http://www.cruisereviews.com/RoyalCaribbean/Splendour26...eandDineBrochure.pdf
) I believe it is also available on the first night in the dining room, but it is much easier to purchase it right away and a bottle will be waiting for you on your first night at dinner.