Johnson caused the Swiss problems all night and provided a number of teasing crosses from the left wing. He also came close to scoring himself.
Wheater was a rock in the defence as they kept a clean sheet at Wycombe's Causeway Stadium.
West Ham youngster Moses Ashikodi came off the bench to score two second half goals as England ran-out 2-0 winners.
On Tuesday night Lee Cattermole started for England U-18's against Turkey in Mersin. Unfortunately England lost 1-0 in a closely fought game.