There's no need to be worried about these bugs! Yes, they're annoying but they absolutely do not harm you in any way. Your vehicle, yes, but not people.
The bugs tend to show up only during daylight and are at their worst in the hottest part of the day - usually between 11:30 - 3 p.m. This is the reason they're attracted to the Disney buses, the heat near the back of the buses attracts them.
When we were at WDW this past May, we were waiting for the bus at the CR. A family with two kids (under 10) were beseiged by the bugs. The parents were waving their arms and yelling and really making a production. I calmly tried to explain that if they just sat still the bugs would leave them alone. I kept assuring the little girl that they would not sting or bite her and showed her one crawling on my arm. After that, she calmed down while her mother was still hysterical.
I hope everything works out for your wedding!