you are in the correct section.
your explanation is a bit confusing. are you trying to use house-wrap Inside the bathroom??
Wood and bathrooms normally dont mix, however cedar is a nice durable wood.
naturally you'll want to keep moisture from forming behind the wood. im not sure what to use for this....
maybe a mold resistant foam insulation.
Obviously the exposed wood must be sealed, and sealed well.
"For a high-moisture environment such as the bathroom, the Western Red Cedar Lumber Association recommends using an exterior-grade finish that is designed to have a good resistance to water. Choose an exterior finish that is also rated for indoor use to prevent exposure to strong off-gassing or fumes in the enclosed space of the bathroom."
This is not my specialty, but if you address situations such as:
-moisture behind walls
-seal exposed wood against moisture/decay
i think you'll be OK.
Also, IMO i dont think house-wrap is appropriate for indoor use. I hope this info was somewhat helpful