A California cell phone violation will result in a conviction on your driving record, but it does not count as a violation point.
The California Department of Motor Vehicles notes that fine for violating the cell phone laws will be $20 for a First offense and $50 for a second or subsequent conviction. There is also a penalty assessment which basically comes out to be three times the amount of the fine plus a state surcharge and administrative fees that can be tacked on. So we have heard from drivers that end up pay around $90 for a first offense ticket.
So while the base fine of talking on your cell phone while driving in California may be $20 but as with most all tickets in CA there are additional costs added to the base fine amount. There are state and county fees typically as well as court costs to process the ticket and thus a ticket can easily be double or in as in this case 4 times the base fine amount.
You mentioned there is the traffic school option for your cell phone ticket however since it does not come with a point being added to your driving record and you are only allowed to take this driver improvement course once every 18 months you may want to pay the ticket and save the option of traffic school in case you get another type of traffic ticket where you want to keep points from being added to your California driving record.