From the California Motor Vehicle Code: Violation Point Count: Exception
12810.2. Notwithstanding subdivision(e) of Section 12810, no violation point count shall be given for a conviction of a violation of Section 27315.
Not having a seat belt is a non-moving violation, therefore you don't get points on your record.
While in most places it will not create points against your license, it may cause your insurance to increase, as it increases the risk of death and injury in an accident.