Flooring Tile - Wonder board or Hardibacker

I am tiling a bathroom. I have a wooden subfloor, and need to put a surface down to tile on. Does it make a difference if I use Hardibacker boards (which I've worked with before a bit) or wonderboard (the concrete boards)? I'm also wondereing if I need a vapor barrier between the wood subfloor and whatever I use?

Either one will work. It is just a matter of which one you like to work with. Hardie is easier to work with IMHO.

No moisture barrier, as that will hinder the stick and cure of the thinset used to set the CBU tile board into, before fastening.
Do not install CBU dry to the floor! It is set into modified thinset.

Thanks for the advice. I went with the Hardibacker boards, and found them to be pretty easy to work with.

Before we just throw out the idea of using a vapor barrier(i know its too late for this job but for future readers there are some things that should be determined)

#1-is there a crawl space under the area you are tiling? If so the use of either a membrane or at the very least a vapor barrier installed underneath the subfloor in the form of 4-6 mil plastic prevents many flooring failures.

#2- is this a summer home that will not be heated??-If you answer yes to this a Membrane becomes even more critical.Once again,at the very least a vapor barrier installed below the floor in a crawl space would be reccomended.

#3- Will this area recieve heavy use by young children where splashing water etc might provide the need of waterproofing??-Here again,a little thought beforehand can prevent a myriad of problems later with Mildew etc.

There are many types of membranes available some are easy to use and others not quite as DIY friendly.A Little research will show you which will be best for your skill level and or budget.