Bailey Wright sent North End in front after 68 minutes but the lead was short-lived as Rory McArdle netted the game's fourth headed goal to make it 2-2, before Hanson had another headed effort disallowed late on.
The visitors looked the more likely to snatch a late winner but Grayson's team also had chances to grab a decisive goal.
"We'll take it - it was a hard fought point," said Grayson. "We got off to a bad start but we showed a lot of character, endeavour and heart to swing the game back.
"I thought it was a great game, it was two teams going head to head. There was plenty of tempo, plenty of tackles and it was very quick. We could've won or lost.
"Both teams had chances and could've won it but over the course of the game it was probably a fair result for both teams.
"We'd warned the players what to expect from Bradford in the air and from certain deliveries but you have to give them credit for the way they attacked.
"We take the draw, it could've been more, Chris Humphrey has been denied by a brilliant save and Kevin Davies probably should've scored but it could be a valuable point come the end of the season."