I think moisture meters work without problems on bamboo such as in wood, but will need calibration in draying oven method. Wood also has variation in density and these devices operate relatively well.
According to the literature, silica content of the bamboos varies from 3.7 g/kg to 45.7 g/kg. Thus, silica is the major inorganic constituent of the epidermis with values between 1.5% (Bambusa vulgaris) and 6.4% (Schizostachyum lumanpao).
Considering that moisture meters are based on eletricity condutivity, the salts can influence the results. So, be aware of this possible influencing effect.
I agree with my colleagues concerning the use of moisture meters based on electrical conductivity and the possible problems due to density and silica content. But just think about the use of moisture meter based on Electromagnetic Wave Technology. Here a calibration is needed too, but there are producer offering moisture meters calibrated for the use with bamboo flooring materials.