Is there any difference between the two? Other than checking your pets in?

Rathskeller Inn you can do it for 31 days while Lakeview only allows 21 days.

does it offer a GA perk like Lakeview, to check all pets in?

I'm sorry, I can't properly answer that since I can't remember and I don't have a gold account to test it right now. Hopefully someone else can answer. :(

Ahh, okay. Thank you very much for all of your help. :)

I just took a look at Rathskeller (did not even realize this was a thing, lol) and you must check in each pet individually, gold account or not.