San Francisco and Redwood City are roughly 30 miles apart. In the Bay Area, in particular, buses tend to work on a city or county level, which would mean to make this trip, assuming buses were conveniently located, timed, and without too many stops, it would involve using several transit systems, unfortunately. San Francisco and Redwood City not only have dozens of other cities between them, but they're also in 2 different counties (San Francisco and San Mateo county, to be specific). I don't want to say we don't have cooperation between transit agencies, but they are at least distinct entities for these services.

A better solution would be the train. Bay Area Rapid Transit (BART) serves many counties and cities, but does not go that far south.

Caltrain serves both San Francisco and Redwood City quite well; however, the nearest station is miles from the Marina district, and depending on destination, would require a transfer on the other end as well.

Of course, I'm sure Chariot involved multiple stops as well, but presumably most riders took it every day, so it was a route that was tailored to the riders of that van, rather than a generic public transit service that might have inconveniently timed transfers, too many stops, or other issues.

EDIT: Actually, it looks like I am incorrect. SamTrans (San Mateo County) actually does go from Redwood City to San Francisco by bus, at least on the 397 and 398 routes, but only midday and it will take almost 2 hours, as it's entirely on surface streets for those ~30 miles (and the terminus on either end is not particularly more likely to be more convenient than the much faster train) http://www.samtrans.com/schedulesandmaps/maps.html