"Glass" won't refer to fibreglass, it will refer to plate glass (as in windows). The key part of "fibreglass" is "fibre", not "glass". Aside from the raw material it's made from (which is sand, like you find at a beach) glass fibre and other forms of glass really have nothing in common. They are very different materials.
Fibreglass is really the same as any standard stubstrate ... (eg: wood and metal) as far as paint adhesion goes, and has more "tooth" than most surfaces, which is a desirable property for paint adhesion. That's your main criteria for adhesion ... don't worry, you would have to hunt down the world's most useless primer or an incredibly specialized primer to find one that won't stick to fibreglass.
You should be concentrating on the other aspects of finish choices. I would suggest the most important of those is to choose a primer that is compatible with your intended topcoat(s). Although you can freewheel with paint and get away with it, there are enough instances where you won't get away with it that it's worth your effort to stick with what the paint manufacturer recommends. Automotive painters, for example, typically use only one brand of paint for all coats.
Were it my project, I would be using a water-based epoxy primer and topcoat, but you certainly don't have to. Your choices are vast.
When priming fibreglass, I much prefer high-solids/high-filler primers that allow you to sand and smooth the finish prior to topcoat. Automotive, marine and aircraft paint makers generally will have these types.
There is a rundown of some common house paint primers tested on fibreglass at the West Marine website. You may find that helpful.
West System-Testing House Primers