To get into some of the bars/clubs... yes.
You can walk thru citywalk or go shopping w/o any additional charge. You can eat at the restaurants w/o having to pay to get into them. But most of the bars/clubs have a cover charge to get in during the evening hours.
I think from what I saw, single club cover charge is usually about $7, but you can get a "party pass" which allows club hopping for $12.
Also, most park tickets (and blue man group tickets) include admission into the clubs, so if you go to the park, you can go party afterwards.
The problem is that on the AP level, the preferred pass no longer includes that citywalk admission from what I can see, only the premier does, so since a AP makes financial sense for me over getting a regular multiday/multipark ticket which would give me club access, I need to include my potential evening party plans into my cost analysis between the 2 passes.