Drywall Topping Compound HELP HELP
 

I am doing a repair around my bathtub in prep for a tile person. I have a
glass block window where one of the pieces of edge metal was not installed.
I installed it and covered it with some 20 minute all purpose, but over the
whole piece of greenboard to even it up I used a topping compound. Same
along a corner near the bathtub, first I used all purpose but to fill void
about 1/4" deep to flush the wall out I used a topping compound. It says
now that I need to read it not to apply it to bare drwyall/greenboard. Did
I goof? I hate to have to tear it all apart and redo it. The tile guy is
going to nail paper and run cement on top and put tile. He just wanted a
corner to wrap his tile around. Is topping compound durable at all?