Probably it will fit. I use my Nikon D3100 with a 18-55 VR + a 70-300mm lens (under the camera in this same case). There are 2 "straps" (Velcro) that will help you to accomodate these items. I hope that this information can be helpfull
There is no way this bag can carry two lenses at a time. It will fit D5100 body for sure and probably with 55-200VR attached. But this is not a carry all bag. Just one camera with lens, spare battery, filter and memory cards. That's it.