Being a member of the media (reporter), I will offer my experience.
Media passes are generally given to credentialed media personnel, particularly national and local media organizations with interest in the event/team.
A team may recognize smaller organizations, depending on availability of space and how "worthy" they deem your publication.
Usually, credentials must be submitted before hand, especially if you're a new reporter/organization.
I know whenever I cover a national event, whether Olympic soccer or a NFL exhibition game or XFL game (I'm not a regular sports reporter but I have handled fan reaction), or some other special event, I need to submit information to get a media pass.
At least that's been my experience.