What constitutes a school zone?

The city of Manhattan Beach has decided to include the church buildings and parking lot of the church associated with a private k-8 school in their VDZ map of the city. They claim the principal said that students are in both locations as "part of school".
Map: http://www.southbayopencarry.org/wp-content/uploads/2010/09/Open-Carry_Public-Private-091610.pdf

Yet if you look up the school on the CA State BOE website it gives a single address of:
http://www.cde.ca.gov/re/sd/details.asp?cds=19753336960736&public=N
1701 Laurel Avenue
Manhattan Beach, CA 90266-4991

Looking at the county assessors map it shows no church buildings as part of that property:
http://maps.assessor.lacounty.gov/mapping/viewer.asp (you must type in the address above).

Can someone tell me how 626.9

"School zone" means an area in, or on the grounds of, a public
or private school providing instruction in kindergarten or grades 1
to 12, inclusive, or within a distance of 1,000 feet from the grounds
of the public or private school.

Click to expand...

Includes other buildings not part of the school ground that students may be as part of their education?
If a class goes on a field trip to the museum, is that now a school zone?

The property line of whatever parcel of land the school occupies is where the GFSZ starts. This has been hashed out before in cases involving the federal GFSZ law, and it would be prudent to assume that the state courts would follow the same rules in regards to the state law.