Can I use self leveling cement in the bathroom of my manufacturd home?

That depends on what you are doing with it. You should be able to level the floor, but you need to make sure the substrate is sturdy enough

If you plan to lay a new floor it does need to be level. That is what self leveling cement is for.

Are you going over the entire floor or just doing spot work? There are other, much cheaper products for small areas. We used the self leveling concrete on a low spot in our kitchen because we wanted to put down laminate flooring. It failed to self level. Because you have to work fast to add each new batch, we did not realize what was happening until it was too late.

We were left with a hump and, after contacting the company, the only thing they could suggest was taking a grinder to it. We tented off the area but the powdery dust still went everywhere and it was impossible to get it down to being level enough for the laminate. It was an expensive disaster I wish we'd have never tried. :(

I don't think it can be applied thinly and work. I had a professional install it in my whole basement and it came out great. they did tell us not to put vinyl flooring down or stone for a year. Hardwood would always be a no no. So unless your bath is a couple of inches above the rest, I would just put a some kind of base down for tile, even if you need to shim.