Military? That sounds interesting!
Do you mean something like an Officer's or Enlisted Men's club?
Really, a military barroom is pretty much like any other...there's a drinks bar, some stools, some bottles in cases on the walls, maybe a pool table or some darts, possibly some steaks and a couple of small dining tables...that sort of stuff. The only thing different from a civilian bar would be the types of pictures on the walls, and possibly the type of music playing (the military one would be louder, more than likely
Since we have no military deco at all, well...wow!
Now as for military clothing...https://www.google.com/search?q=sims+4+ ... KZQo&tbo=u
Here's a speed build for a military base. https://www.youtube.com/watch?v=jDsSOM1Glu0
You could probably use some of the ideas in those two builds.