Matushka & Batushka are old-school endearments for parents. I've heard fathers (both priests and parents) refered to as "bat'ka," which can be an endearment, or can be disrespectful.
You will notice if you read a lot of Russian classic lit that parents are refered to as matushka & batushka. It transfered over to priests, as religion was an integrated part of life, and people saw their priests as second fathers.
I personally have never called my parents batushka & matushka... though they are that in both senses of the word. Neither have I ever called my grandparents that, although Dyeda is a priest.