I ripped up all the existing tile, it was small tiles that I had to chisel up. There is quite a bit of thinset that is bonded to the wood floor and its impossible to get it all up. If I try and chisel it all off I end up ripping up the wood and making it worse.
I think the wood sub floor is sitting on another older piece of sub floor but i'm not sure.
What are my options here?
- put cement board over it (do i need to put waterproof membrane?) and then tile it? If I do this the bathroom floor will be slightly higher then the hallway floor.
- Can I use self leveler on the wood subfloor and then tile over it? it would probably be the ideal height.
- Do I chance ripping up the subfloor and doing cement board and then tile?
Am I missing any other options?

 

Welcome to the forums! You will need to achieve a reasonably flat floor for the tile. You could use Ditra for the uncoupling membrane and keep the rise in the floor to a minimum, as opposed to using 1/4" Durock or similar.

You really need to find out the layering of your subfloor. If you have a floor register, it will help you see the layering without any damage. If not, you can drill a 1" hole in the floor and visually see the layers. CBU and tile will cover over it later. Let us know what you have.

 

This is the last thing you should be worried about if you want a lasting tile job. As Chandler said, we really need to know what the layers of the subfloor are plus the size, spacing and unsupported span of the floor joists.