The problem is if you take a boat to Epcot, you have to go through the park, using a day of your ticket, and if you don't have park hopper, it'll use 2 days. Not cool. It's also more hectic, and anytime you have to transfer, it could take an additional 15-20 minutes. Go with the most direct route possible. Now if you have reason to go to Epcot, then by all means go for it.
Also keep in mind, if the Magic Kingdom opens earlier or closes later than epcot, which is very often, you will NOT be allowed into epcot to get to Y&B Club. Epcot goes by it's hours, and is really not inteneded as a transportation hub for those resorts.