Sorry I posted a wrong URL in my post - am looking for correct one now to add back in.
Service is included in SBP drinks ordered as noted in this post in that super long thread I did link
http://boards.cruisecritic.com/showp...&postcount=491
My reading of that thread (and not my personal experience) indicates that your SBP is good for the day you board. I don't recall alcohol being served anywhere on disembarkation days, so perhaps it ends at midnight the day before you leave?