Unfortunately, when I use Iconic Weapon and apply Wrecker’s Crowbar to a custom character, the character in question does not receive a bonus to their Melee or Agility Damage Multipliers. Whilst the crowbar does not say that it grants a bonus to the Agility Damage Multiplier, and as such one could potentially say that on a strict reading of the rules, it ought not apply such a thing, a similar case cannot be made for the Melee Damage Multiplier, for it functions as a Club, its throwability and returning properties notwithstanding. Given a Club grants a +1 to the character’s Melee Damage Multiplier, there is no reason that the crowbar in question should not be adding such a bonus; therefore, this strikes me as a significant error which is in need of reporting.
Hi there drakkoniss3!
It is correct that the weapon does not add any bonuses as you describe, as per our friends at Marvel.
While I’d agree that a throwable club iconic weapon ought to add to the Agility damage multiplier to the sheets to be consistent with other Iconic Weapons, that’s how it’s written in the Cataclysm of Kang book for Wrecker’s entry so this is something you should report for errata on the Marvel page (https://www.marvel.com/rpg, post about it with the FAQ Submission). When errata gets posted by Marvel, Demiplane is usually very quick to implement the fixes on their own databases.
In general, the Bonus Multiplier from weapons are not applied to the sheets for the characters, because it is not a constant/permanent bonus. Mighty or Accuracy would be applied, but the +2 for a sword would not. That bonus only applies when they are using a weapon. It should be manually applied whenever they use a power or attack with that weapon.