Carol, I think California has a mediterranean climate so should be okay for most of the southern Australian species.
Grevillea dryandri grows in sandy well drained soil and is an equatorial savanna plant, that's hot, very wet and humid wet-season, and a hot dry, dry-season (winter) . One of our local Grevilleas (G. pteridifolia) mainly grows as a small tree in swamps and is waterlogged or flooded for most of the year. It varies a lot between species.
