Vegetable oils will go rancid and that can ruin your board
I'll second this. Perhaps not ruin but rancid oil is not something you want to deal with in a cutting board.
Add a little wax to the mix and it won't hurt. It only adds a bit of longevity between treatments.
If it needs oiling use mineral oil and make sure you wipe it VERY WELL because mineral oil is a laxative
Awww.... Come on now Jennyema, Don't have them wipe off the excess. That's half the fun of using mineral oil.
As I said I don't know squat about bamboo but dealing with wood boards I can say they don't do well with "Natural" oils in the long run.
Mineral oil and beeswax are your friends here.