Watch the Smashboxx link above. I don't think simply asking for permission from the TD automatically makes you a media agent or opts you into the lengthy media agreement the production companies have to deal with.
The rule has nothing to do media agreements though. Makes no mention of them so it's not as though a signed agreement is required for someone to be official media at an event. The players aren't aware of who's being paid and who isn't, or who's signed a contract and who hasn't, so why should that be a factor? If the media is TD-approved, it's official media.
Put it this way, if the TD said at the players' meeting that "Joe is going to be filming the lead card for us, thanks a lot Joe", then shouldn't the players take that to mean he's official and they should treat him as such? Much different than if Jim just shows up at the park, speaks to no one, and starts filming the round on his own. The players would be under no obligation to cooperate with him at all.