I maybe misreading your post, but I'm pretty sure the "Club Kitchen" is not just any galley.

IIUC, the phrase refers to a small area of displayed food for the Club World customers usually consisting of snacks of various kinds. In my personal experience, this is crisps, popcorn, candy bars, granola bars, ice cream, and a few cold juices and waters. It's handy when you're restless between served meals. WT and WTP passengers are not supposed to partake. And F passengers either since they should be able to get ala carte menu items at any time (I think.)

What you're referring to as a visit "to the back" when travelling WTP is not the Club Kitchen as it is generally at the rear of CW, so should be forward of WTP.