If you gave bruce wayne a day and information about iron man he would find a way to even the playing field.
Iron man with all his technology was beaten by a shield and a metal arm in civil war.
Bruce wayne would bring his power armor and find a way. I laughed at the kryptonite spear in batman vs superman but hey superman ended up dying.
Tony only chance would be to attack with everything he had at the same time and all of his suits and be at end game level of technology.
What happens when you take two rich dudes with money and tech and make them battle each other out. Wayne is good at appearing and disappearing without notice and our pal Iron Man can fly and blast fire out of his hands. So who would win? I don't know but this thing is forcing me to pick a side so yeah. . .
As the question phrases the alter-egos of these two heroes, I believe the fight would be between them without their suits or their gadgets. Therefore it is undeniable that Bruce would wipe the floor with Tony's corpse as a master of nearly ever martial arts and an absolute unit of a fighter. A fight between Iron Man and Batman would be more interesting.