note, i'm not talking about multiple blooms on a single stalk. the variety i grow here will have 2-4 blooms per stalk and it depends upon bulb size, but also how much energy the bulb was able to store over the growing season. many bulb plants will reform the entire bulb each season and that is when they also form the flowers for the next cycle. i don't think the amaryllis does this quite so aggressively because it seems that the outer layers persist a while longer, but i'm pretty certain the inner layers will split to form new bulbs that eventually show as separate bulbs when the outer layers finally do wither away into tunics.
i am talking about multiple flower stalks. those i've only seen one per bulb. if examined more closely all bulbs that appear to have multiple stalks are more likely just as i mentioned above, two bulbs smashed closely together. if you pulled the plant out of the pot and removed the outer tunics/layers you'll find more than one bulb in the middle. if this isn't the case i'd be very surprised and also very interested in examining the plant closely. i'm also sure that many people would be interested in such a plant because more blooms are always desired...