I've a lot of experience with bamboo..... I sell it every day and I've
set up many displays with it... To be honest, my experience has shown
me numerous times it really does not do well underwater, even in the
absolute healthiest, most well-monitored planted tank. It will
probably hang around for a few weeks, languishing and getting paler and
more overgrown with algae... leaves starting to rot... then it will
slowly die. It tends to do best above the water or as a potted plant
in a non-sunny window (doesn't like direct sun).