There are some Non-Conformist records for Devon on Findmypast, Ancestry, FamilySearch & BMD Registers(The Genealogist).
This is a listing of Non-Conformist records held by Plymouth Records Office. You often find that Non-Conformist records are recorded under the Circuit rather than in a specific Chapel.
I've had a quick look at Non-Conformist records on Findmypast and can't see a birth or baptism recorded for a William Hayes c1805.
I believe the Bible Christians were not founded until 1815 and were a break away group from the Methodists