The 37-year-old was unable to prevent Paul Lambert's side from warming up for the play-offs with a deserved victory.
Delroy Facey and Leon Knight both scored in the opening 25 minutes as Wycombe looked every inch a side heading for League One football next season.
It was just six minutes before the Bantams were behind, as Wycombe debutant Matt Phillips slalomed his way through a non-existent City midfield, before releasing Facey to smash his effort in off the post to give the play-off contenders the lead.
Quite where the Bradford midfield was when Phillips received the ball remained a mystery, but to their credit the visitors battled back and only a fine save from Frank Fielding denied Wetherall's ambitious long-range piledriver.
Wycombe continued to dominate and it was little surprise when they eventually doubled their lead through Knight's close-range effort.
Just moments after home skipper David McCracken had headed Mike Williamson's cross against the City crossbar, Knight prodded home from six-yards after McCracken had once again caused panic inside the visitors' penalty area.
Wycombe looked set to run riot with City's defence in disarray, but with the play-offs in sight, they took their foot of the pedal and instead allowed the visitors a way back into the game just before the break.
David Brown, on as substitute for the injured Barry Conlon, ran clear of the Wanderers defence only be taken out by home stopper Fielding.
Medley dispatched the spot kick with minimal fuss to halve the deficit and give his side a goal they rarely looked like scoring.
The goal gave Bradford a much needed injection of self-belief and only a stunning acrobatic save from Fielding prevented Medley from clinching an equaliser after the midfielder unleashed a stinging effort from 18-yards.
Both teams pushed forward in search of further goals with Wetherall being deployed as a striker in the dying stages as he looked to end his career on a fairytale note, but the giant defender was unable to bring down the curtain on his career in a blaze of glory.