1) Seminars - you can catch those a level or more above you (and then some) in the restaurants and bars during down time. Don't force yourself and your JV offer on them. Introduce yourself, and start a little small talk ... better yet, find another attendant that may have networked their way into the player's camp, and ask them to introduce you. The important thing is to not come off to strong ... talk to them like the guy and girl next store, and let things happen naturally.
2) Get to them, indirectly - trying building a rapport with a player's project manager, affiliate manager, webmaster, or just a more approachable marketer that's clearly connected with the player ... once again, it shouldn't be 'Hi ... my name is Joe Blow, and I've got this great new project that's launching on ...'. Instead, make it all about them until you've built a rapport.
Supplemental answer - Promote one of their products, first (only works if you have the resources to perform this task successfully enough for them to notice - see paragraph below. ).
Of course ... the effectiveness of the above two methods rises commensurately with the level you've reached in your own self and product branding. So start building a solid business ... first, before ever expecting to line up high level JV partners.