OHAI! So, uhm, I don't believe Jess and I ever talked about anything with her and Terin but seeing as he's about to join her little group, I'm sure figuring out if they're going to hate one another or not is the least of what we should do haha.
Honestly, Terin's pretty easy to get along with. He's a bit apprehensive of everyone who isn't in his clan (other elves included), but warms up pretty quickly... so long as they're not human. It takes a bit longer for them to get on his warm side, but until then is he by no means outwardly aggressive. He'll just be kinda standoffish.
Though growing up in Denerim gave him the opportunity to see and speak with dwarves, he never really got much of a chance to. I know there won't be any of G3's dwarves at Lanaya's clan when the group splits up and arrives there, but once they reconnect he'd probably be intrigued by them. And he'd probably be more apt to warming up to Falina than any of the other two because she is a Warden (after meeting with Faer and Lalin when they reach the clan he'll see being a Warden as a higher calling... rising above the prejudices of the world to help anyone blahblahblah and will thus think more highly of them... even human ones lol).