Pretty much. The series format is a little odd. Sword Art Online II is a sequel series, but it behaves more like a season two, and contains plot arcs 3 and 4, from the third and fourth books. Personally, I'm just going to refer to the show by plot arc as opposed to season, for clarity.
Now is a good time to watch the Gun Gale arc, since it just finished. The new arc just started 3 days ago, and so far I'm not blown away. It broke the pattern of starting a new arc with dropping a bomb at the end of the first episode.