I have searched the threads and found some info on garrisons but not really what I was looking for.

Is it safe to say that if you are grouped with someone you will be able to use the buildings they have in their garrison like the mage tower?

Also if you are grouped with someone can you take advantage of the quests in their garrison(kinda like Wildstar), or are those just for the garrison owner?

If it has been covered somewhere else, I apologize.