He subsequently read divinity, studying among the Bonhommes whose house stood on the site of the present Wadham College.
He obtained royal favour and was made chaplain to Henry VIII, who, on the foundation of the bishopric of Bristol, selected Bush as the first bishop of the new see.
Bush's replies to certain questions relative to the abuses of the mass, proposed in 1548, were largely those of an orthodox Catholic.
The following year, 20 March 1554, a commission, of which Stephen Gardiner and Edmund Bonner were the chief members, passed a sentence of deprivation on him.
He was buried near the grave of his wife, on the north side of the choir of Bristol Cathedral, where his mutilated Renaissance monument, bearing his effigy as a decaying corpse with a tonsured head, still stands.