Being blessed by a deity in the lower city shrine should add that deity's tag to the character with the blessing. For dialogue and such.
Also, I'd recommend Gale have the Mystra tag permanently. Ditto Halsin and the Silvanus tag. If Jahiera and Minsc have a deity from prior games, they should continue to have that tag in this game. Don't forget Minthara and her Lloth tag.
Also, any character with a diety tag can only be blessed by their own deity.
All this for +2 to saves in act 3.
