The link below explains how the TOTAL tax bill is calculated for a specific property you might consider purchasing (also covers supplemental tax bills when you buy a property and the Prop 8 tax reduction process):
"Estimating Property Taxes in CA"
This is completely plausible, however , the tax assessor reassesses all homes on an annual basis. If you request an appeal on your assessed value, it may take some time.
Either way, I'm happy to help with market comparables.
Let me know if I can help further..
I don't know exactly what your question is, but you might want to look at http://www.MyTaxCollector.com . This site will show you quite a bit of information regarding any property in San Bernardino County.
Don't hesitate to contact me with any questions.