To my knowledge the Bilderberg conferences operate under Chatham House rule, with the goal of encouraging openness and information sharing through a certain degree of anonymity to the outside world.

In practice this often means that attendees can reveal what was discussed, but not where, when or from whom they obtained information.

So if you happen to have the chance to talk with an attendee, you could potentially learn what was discussed (ofcourse without any references to where it was discussed) ;-)