by the book, you can have bonds only with other PCs, but a lot of people here changed this, having bonds not only with npcs, but also with organizations, objects, ideals, gods, and so on. So, well, if it's an issue for you, talk with your group and see what they want.
you absolutely can have more than one bond with a single pc. Every bond adds a +1 to your aiding roll for that pc.