ipad and ihpne

any ways to access media player on ipad or iphone on wifi or remotely via 3g?

Only way you could is to install Exposed (a VNC app or the like) but that will not be fluent.

Why not just use VLC on your iDevice?

You mean vlc player with local files? I already have it. Or Can I connect vlc with
Media player

No you cannot “connect” VLC with Media Player. 

Couple solutions:

http://itunes.apple.com/us/app/vlc-streamer/id410031728?mt=8

http://itunes.apple.com/ca/app/air-video-watch-your-videos/id306550020?mt=8