Whilst it's certainly possible to use SwiftDeck Brazil Walnut or Brazil Teak tiles in a bathroom, there are two aspects that need to be taken into consideration.

Firstly, since there are gaps between the individual wood slats, cleaning may be somewhat more difficult than a normal smooth surface.

And secondly, any wood product should be allowed to dry out from time to time otherwise it's possible that you could experience some mold or mildew, especially in bathrooms which have little natural light.