Salts will increase boiling point of water solution that depends on number of ions in solution.
Ammonia is a gas and
1 - practically does not dissociate in water solution (degree of dissociation do not influences substantially on boiling point). Only for extremely low concnetration of ammonia you can treat it in the same way as salts in solution, but then the boling point practically will be the same as bp of water.
2 - other law should be used for calculation of boiling point for more concnetrated solutions. Moreover this law give wrong result without specific corrections.