You were lucky. I have been hit more then once with thrown items and yes they do hurt.
Glad you are ok. Just remember you never know what kind of knuckle head you are dealing with that would do something as stupid as throw an object at a biker.
I think for them to have been rednecks they would have to throw Sundrop or Mountain Dew bottles. Of course, it's a nice touch if the bottle was being used as a tobacco spit reservoir. My brother once had a Pepsi bottle thrown at him. I can only imagine what kind of depraved individual drinks Sprite, especially one who would waste half the bottle on one of us.