There are no references to George & Christian on rootsireland. There are references to a George who might be the George in question's father and his father who might be James. I cannot say with any certainty that the lineage is correct.
In Canadian Census records their descendants religion has been given as either Church of England or Methodist.
I did send a query regarding this research, about a month ago to John Grenham who was found on the apgi.ie website. He never responded.