[toni-a]

You surely won't go wrong with Canon  100mm macro, although with close focus abilities of 24-70 such shots are feasible although not real closeups of wedding rings I include in the frame the wedding invitation to make a good setup, just wedding rings shot in macro mode is a boring shot IMHO.

I use for those shots a flash pointed upwards plus a a flash diffuser like this one on the flash 

it works pretty well and of course using flash, shutter speed and stabilization aren't things to worry about, so yes 100mm macro would do the job pretty well, I actually use it extensively


If I want to suggest you one more lens it would be a fisheye, you will use it for three or four shots not more but they will love them, for the dance floor, the fisheye can give you amazing captures

my setups for weddings was Canon 7Dmkii, 8mm fisheye, 17-55f2.8, 100m macro, and as backup camera Canon 5D plus 24-105f4L IS, , plus flashes and reflectors of course 
I think if I would do wedding now it would be 7D plus 8mm fisheye, Canon 15-88, Canon 50mm f1.4, Canon 85mm f1.8, Canon 5D plus 100mm macro mounted on it , with 24-105 in the camera bag as a backup plan