I accidentally glued cpvc with PVC cement, not realizing there were specific cements for each. Now the Sheetrock is up and painted so it would be a pretty good chore to redo. I will only have my water heater set at 120 degrees and I know PVC and PVC cement are rated up to 140 degrees. Is there any reason why the PVC cement shouldn't hold?

Yes, it will burst.

The "glue" is not really a glue, it is a solvent that softens the pipe and fitting material and they "weld" together. Being two different materials the PVC glue or cement will not soften CPVC, therefore the materials will not bond together.

Better turn of water and redo before a pipe burst apart and floods the place.

Specialized cement for CPVC. I'd fix in a concealed space.