I don't velieve that there is enough sugar in any natural sap to make wine, but it would be simple to evaporate off some water to increase the concentration. You wouldn't have to get it to the syrup stage. You might talk to a sugar house operator about bopling some maple sap to about 20 or 25% sugar.
Speaking of exotics, have you ever thought of kumiss, fermented milk? I started some, but I didn't jave a chance to finish it. Cow's milk is not sweet enough. Mare's milk is what is usually used, and there are other varieties.