OM- I have yet to be impressed by the "hiking clubs" in Sacramento area that you find on the internet. I was a Sierra Club member for a few years, but they seem to focus on day trips and are more socially oriented (long drives for a short hike with lots of chit chat). If that is your style, then maybe check them out.
My meetup groups are different - while there are tons of people who just dayhike, there are also many who backpack, and are actively looking for other backpackers. The way to increase the pool of backpackers who are compatible with your style is to network on the dayhikes. The entire goal of the meetup I run is to meet other people with similar interests, hiking is secondary. There are many people who have stopped hiking with the meetup so often because they met people to go have fun with off the calendar.