I think you may have an insect called scale on your lucky bamboo. I have attached a picture from the University of Florida taken by Lyle Buss. (this paper has a lot of useful information mostly related to ornmamental plants). There are many different types of scale which affect a diverse group of plants.
I haven’t seen scale on lucky bamboo before, but the description makes me think that it is scale. You can get rid of scale with an insecticide (be sure to find one safe for lucky bamboo — your local garden center should have one) or you can take a soft rag with soapy water and wipe the lucky bamboo stalks off. Either treatment should take care of the problem. I would however, watch the lucky bamboo for a few weeks — since the scale may have dropped some eggs.