The link that showed the 90 employees making $300K or over is a link to a page about San Francisco city employees specifically, and says there's 40,951 total. (And it is 90 exactly according to that page.) So is 0.2% of workers earning that much a lot compared to tech companies, do you think?

How about employees making $200K or over? That's 1790, or just about 4%. $100K or over? 15997 employees, or around 39%. So over 60% of SF city employees make under $100K. The median salary, in fact, is just under $86K.

I could be wrong, but I suspect that's lower than Facebook's median salary.