I have thoroughly rinsed all my yarns after dyeing, but there might be occasional crocking (some colour might rub off on your hands). This does not mean that the yarn bleeds; there are simply some excess colour-pigments still stuck to the yarn.
For best results briefly wash and rinse your finished project with a little of a mild, ph-buffered soap. That way you will enjoy your new garment for a long time.
This way for more informtion on the specifics of indigo-dyed yarn.