Under the IU's "revised rules", players will not be forced to hand over personal data, a move the Rugby League Players' Association warned risked infringing upon civil rights.
"They are making a difficult job for us much more difficult than what it should be," Bennett said of the IU. "I can't talk for all clubs, just the one here.
"We are so conscious about our image, so conscious about all the things we have to do and they need to help us, and that is not happening right now."
The IU's backflip comes after their botched investigation into the Arizona arrest of South Sydney players John Sutton and Luke Burgess. Souths were hit with a $20,000 fine on Monday, but the players escaped suspension.
An NRL spokesman said clubs were already required to inform the NRL when they knew a breach of the NRL rules occurred.
But the revised code will require clubs and players to report to the IU any matter which it "reasonably suspects" may constitute a breach of the NRL rules.
However, Bennett backed the NRL's appointment of a wrestling coach to work with referees and the match review committee. The main brief of experienced wrestling coach Milton Dymock will be to explain current grappling trends and predict new ones.
"I think that is a good idea," Bennett said. "The game is changing all the time and unless you are at the cutting edge you don't realise things are happening until months later.
"And some coaches out there are quite sophisticated and have a fair bit of science behind them about how to grip someone by the finger or elbow or whatever.
"Unless you have a mindset for it you don't see it."
-AAP