Having a dispensary near a school is in violation of Title IV the Federal Safe Schools Act of 1994 and various state laws that are linked here
http://law.jrank.org/pages/11811/Marijuana.html
A dispensary in general is a violation of Federal law. The Feds are welcome to bust them if they are near a school or miles away from a school.
The question is are these a violation of California law. I haven’t seen anything yet that suggests that.
The Federal Safe Schools Act of 1994 is in violation of the US Constitution of 1787.