Last time I played, Xzar (from BG1) meets me a little outside the Galvery estate in the Docks district and offers me a quest to retrieve his friend Montaron from the harpers. As soon as i do that, the bird i rescue turns out not to be montaron but a harper in disguise and she kills Xzar. immediately after, another harper comes up to me and asks Jaheira to meet Galvery inside his estate which follows with a fight with Galvery...

This time however no harper came up to meet me. is this ok? will the quest follow up by itself?

The Galvery fight, I believe, is tied to the Jaheria romance. I would assume that you aren't as advanced in the romance as in your other games.

The Galvarey fight is actually the end of the quest if you are not in a romance with Jaheira. Since all of this happened so quickly, I assume that you are not; otherwise, things would be much more drawn out.

Does the romance carry on into ToB? From what you say I must be having on with her as stuff kept happening after the galvarey fight, but I'm now in ToB and I don't think I finished the romance.

Jaheira's romance is pretty much dealt with in Shadows of Amn. In Throne of Bhaal you might get some chit-chat, but an in-depth quest or story as in Shadows of Amn is nowhere to be seen.