I see this question a lot. The answer is no, he is not.
In 1993, a Yorkshireman named Steve Murray was on the TV talent show "Stars In Their Eyes" as Meat Loaf. Later, to help promote his tribute act, Steve changed his stage name to Steve Steinman. Under companies house, his business "Steve Steinman Productions" names Steven Murray as the sole officer.
He has never worked with, or had any association with, Jim Steinman.
Steve has in fact said a few unkind things about Jim Steinman's Bat Out Of Hell in promotion of his own work.