Wigan Warriors coach Noble, returning to the Grattan Stadium for the first time since his departure last April, watched his side race into a 10-0 lead inside 13 minutes only to fade in the face of a terrific Bulls onslaught.
Vainikolo took his remarkable try tally to 134 in 135 appearances and captain Paul Deacon scored his 2,000th point as the Bulls made it three wins out of three to top the table.
Great Britain prop Stuart Fielden, who like his boss was making his first return to Bradford, responded by scoring two tries - his first for the Warriors - in seven minutes to threaten a fightback, while Bradford hooker Terry Newton also scored against his old club.
Noble had expected to be nervous on his nostalgic return but any anxiety would have been removed by a whirlwind start from the visitors.
Second rower Bryan Fletcher pounced on Thomas Leuluai