Re: congratulations or best wishes
Indeed. Traditional ettiquette, which is rarely observed, is "best wishes" to the bride, and "congratulations" to the groom.
Miss Manner wrote a funny column on this once, and just as Dave said, you don't want the bride to think you are saying "Thank goodness you were finally able to land a man!"
Truth be told, I say "congratulations" without thinking of this very often.
I'm not a teacher, but I write for a living. Please don't ask me about 2nd conditionals, but I'm a safe bet for what reads well in (American) English.