I think you're confusing marginal tax rate with effective rate. As a single person in California making $150k p.a., your take-home pay is about $95k per year, or $7,900 per month.
It doesn't really make sense to me to factor things out like that. Sales tax on groceries should be accounted for in the groceries budget. Property tax is part of your housing budget. Car registration fees and bridge tolls add to your transportation budget. Income taxes are different because they determine how much you're actually being paid each month.
If you're paying 1k for food & everything else; that 1k is definitely including sales tax. And 8% of what you spend is definitely not 8% of your total income if you're saving as much as possible. You're double counting taxes.
I only make $50k and I'm saving $30k a year. I'm fairly sure if I quadrupled my income I could at least double my savings.
~35% goes out to your standard/official taxes
then you pay ~8% of whatever you spend to cover sales tax
then you pay ~2% of whatever your home is worth for property taxes (renters don't see this as tax but its built into the monthly payment)
and then there are lots of other smaller things like the car registration fees, bridge tolls (that may be a more of a bay area thing).
Anyhow its not exact but the way I budget is that 50% of my income is for actual spending/saving and have found that that ends up being about right