I don't understand the last bit of your question "so reviews can't be used", so I'll answer the first bit about building trust.

For the to-be-married couples, trusting who will come to their wedding is really important because of the potential risk associated with having their event ruined by "bad guests".

Building trust = reducing that risk.

How? Couple ideas:
1. Require the guests to link their social media presence. It's functions like a background check. One filter that could be useful here is to only allow linking to accounts that are at least a year old (or whatever period you choose )

2. Video interviews could be a good way to build the rapport also

Beyond the trust building, you can also reduce the risk by doing things like the following:
1. Have the guests join only part of the festivity that are less risky (bachelor's party) but still part of the culture
2. Have them seated in an area that can be controlled
3. Make explicitly clear that if the guests do any disruptive behavior, they'll be removed from the event
4. Have a representative of your company be present at the wedding or stand-by in case problem arises

Hope this helps.