No idea mate. I would presume it would be tax free or deductible -for you at least- (as long as they had the receipt for it etc…) - I am not a certified tax accountant in Taiwan so I’m not sure how it would work here if there is an allowable threshold etc…
Also here is the relevant law for the meal allowance
But of course. Take all I say with a grain of salt and check with a tax accountant in Taiwan if you are beyond curious.