Ok, I have the same problem a year a go. Is really simple (sorry for my english, I'm from Argentina and I don't manage the lenguage very well).
When you want to put a bridge in a single layer board you can use the "via tool". Simple put a via (this put you in the component layer), move in the direction you want and place a via again (this return you to the cooper layer). Then, yo make the bridges visible in the component mask I put a line whit the "place line tool, previously selected the component mask layer. I have a couple of circuits done that way, if you need an example just tell me and I give you my files. I hope that this help you. Good bye and good look!
