We were on the Destiny last May and I can whole heartedly recommend the drinks package we had the real drinks, Bombay Saphire Gin, Jack Daniels so I dont know where the other person went, fair enough you got the wine by the glass at dinner, but they were very attentive and always filling up your glass wihout asking. The wine was alright by my standards but i am not a wine buff. I do not drink that muCh, but i thought i definately got my monies worth. So much so we are going on the emerald this year and have booked the package again. Hope it help.
You cannot purchase onboard, must be pre-booked and paid. Be warned, you only get the cheap brands and house wine by the glass at dinner.