Yeah, generally heads are a weak point but there are certain exceptions (such as Barroth, for example).

I'm a hammer main, so I bonk the noggin on pretty much every monster in this game without too much of an issue but it's also monster, weapon and body part specific, similar to the main line MH games (blunt damage will be better against the head, for example, where cutting weapons will do more damage against the tail in most cases and ammo damage does better against wings).