I have two sets of saddlebags - a small set of Willie & Max and a set off a stock V-Star 1100 - Both are the vinyl type and both are bolt on.
I riveted a thick plexiglass piece covering the backside of the saddlebag (inside), drilled two mounting holes and used the rubber part of the stock signal light stem as one bolt on point and the upper rear shock mounting point two.
I did have to move the rear signals to the rear tail light area.
There are some saddlebag support that come up on ebay every once and awhile that has a place for the rear signal lights to be relocated to.
I'm not on a computer that has pictures of my set up to attach to the post, but if you are interested, I can post later.
Mike