135mm and 85mm are both good lenses for tight shots of one or two people. For shooting 5 or so 35mm will be your friend or a 50mm if you have them in two rows. Either way having a good coverage from wide to tight is what you need. So you have a good tight lens & your wide (24-70) is not what you are looking for.
The price of buying a good 50/35mm prime versus selling your tammy and going for the EF 24-70L II might be within reach? Lots of wedding use in that lens. Or get a good wide prime and a second camera?