I am removing wallpaper in an 80 year old house. Underneath the
wallpaper is plater walls. In many areas, the top coat is cracking, or
buldging away from the horsehair base. The base is still solid and
intact.

I had a guy over to see about restoring the walls. He said he will
hammer out the buldges, tape cracks and then go over the walls with
two coats of joint compound and sand.

Is this a standard procedure? I was just reading an article on line
saying that joint compound is meant for drywall, and the real way of
dealing with plaster repair is to use plaster products.

The thing is, I asked him this, and he said that he doesn't have
experience with plaster, all he knows is that a plaster person is alot
more expensive than he is, and a plaster project is not a DIY project.
but, his procedure will still work..