Resolution vs Bitrate. What is better for good video?

I'm going to a wedding on saturday. I wanted to shoot some video while I'm there. My camera is a nikon aw110 the best two options of video are 1080p/30p@ 15Mbps or Iframe 540/30p@ 24Mbps. I plan to edit it at 1080p. What is better? Is lower res high bit rate better than high res lower bit rate?

1080p is far better. That is the resolution which has more pixels. 1080p is also considered HD. The 540 will just look like an older video and be very poor in comparison.

You've got a tiny lens with a tiny imaging chip and I imagine you'll be recording some of the wedding indoors - it's not a great combination! Try recording some sample videos with all your options and see what they look like - this may be a case of "less is more".