[The Philosopher]

Cyric did not grant any priests of Bane powers, no. He was viciously opposed to any and all clerics of Bane still in activity, so much so He encouraged two Banedeath pogroms against any remaining priests of him in the Moonsea region. The bitterness between the two clergies goes back a fair bit.

Rather, what clerics of Bane remained were, like as not, to simply convert to Iyachtu Xvim, his son, or to Cyric himself during this interdeium. Even then, Xvim had to be released from Zhentil Keep in 1368 first in order to become a lesser God and be actively worshipped across the world as such.

EDIT: Aaaand I am ninja'd by the boss. Of course. :P