As far as I know, the cutscenes that are skippable are the same from version to version. As a general guideline:
Boss Spawning CS are skippable
Miniboss Spawning CS are skippable
New Area CS are skippable
Dungeon First Room CS are skippable (Dungeon Entrance CS, on the other hand, when they occur, are generally NOT skippable)
Master Sword CS is NOT skippable
Epona Taming CS is NOT skippable
Post Blizzetta CS is NOT skippable
In short, most CS are skippable. The *MAJOR* plot points tend to not be (Master Sword, Ilia's Memory Returning, etc.)
In general, try it (-) on Wii, (Start) on GC and if not it'll do nothing/show a message (upper central part of the screen), no harm in trying.
Also note that some CS are only partially skippable (Ordon Spring Portal, for example) in the beginning half, and some are partially skippable in the later half (After Kakariko Village Portal CS)