Vale set up camp in the City half after only three minutes in what would be the trend for the first half.
Billy Paynter was almost rewarded for chasing down a David Wetherall pass back when Paul Henderson's clearance rebounded off the forward but fell wide of the goal.
Lee Matthews should have done better two minutes later when his free header from a George Abbey ball flew over the cross bar.
Chances went begging throughout the half as the Valiants pinned back a lacklustre Bradford side.
Nicky Summerbee finally created a chance for the visitors when he broke through on the right in the 43rd minute, but Jonathan Brain brilliantly saved his low drive.
Vale responded quickly and had two more chances before the break. Both Jeff Smith and Michael Walsh went close but poor finishing let them down.
Bradford improved in the second half and challenged the home goal straight away.
Steven Schumacher's 50th-minute long-range effort forced a fingertip save which was made difficult by the swirling wind.
Port Vale should have taken lead four minutes later when Matthews played a ball across the face of goal, but Paynter failed to get a touch allowing Darren Holloway to clear.
The Bantams took the lead against the run of play in the 61st minute with both substitutes involved.
Owen Morrison crossed and with the Vale defence failing to clear, it was left to Danny Forrest to slot the ball into Brain's bottom left corner from 15 yards.
The Vailants continued to create chances up until the whistle but the lack of clinical finishing meant the visitors walked away with the points.