While nearly all organic waste can be vermicomposted given enough time and preparation, a home worm bin like the WormBag should probably only be fed nonmeat, non-dairy food waste.
Generally, it is a good idea to diversify the food waste you put into the WormBag: a good balance, in terms of volume, includes approximately 80% food waste and 20% bedding (such as shredded paper, cardboard, coco coir, plant leaves and other carbon-heavy materials). It will help aerate the food waste, keeping the pH neutral and making your worms healthier.
If you have any doubt, ask yourself these two questions: is this waste biodegradable? (Would it get decomposed in nature?). Is this waste of plant origin? If the answers are yes, then you can put it in the WormBag. Pay attention to the reactions of the worms after a few days.