I doubt that Bannon has very much sway in Utah.
The fact is Hatch stayed with Trump, and was selected to "designated survivor," remaining off site during the inauguration in Wash. DC of President Trump.
Unlike Romney, Hatch is a Utah person. Romney has never been a Utah person, aside from his vacation home in Park City and his role for the Winter Olympics.
I doubt both would remain in a race and fight against the other.
Bannon might well find Hatch deciding to retire at age 84 and Romeny get the nomination.