My answer is "Yes & No"
No, if by "belonging" to a course means you get special privaleges at a semi-private. My experience is that you are still faced with difficulty getting tee times, (especially on weekends) closely spaced tee times (creating traffic jams), and the dreaded "Outing". Most semi-private courses agressively market themselves to corporate and charity groups. Our local semi-private is closed to the public (including members) two or three days a week during the season. So a resounding NO to semi-privates.
Yes, if you can see yourself clear to join a private country club. Here you will find ready access to a much better conditioned course, meet lifelong friends with similar likes and wants, many fun & competitive tournaments, and great social activities. It's great to show up, be addressed by name, and have your clubs cleaned and ready.You must, however, get past the cost. First there's the initiation cost. Often all or part of the initiation cost is equity, meaning you get it back (sometimes more) upon resignation. The current economy works for you here. Many/most clubs are discounting upfront fees to attract new members. I don't know how old you are but, most clubs offer very attractive "Junior" rates. Then there are monthly dues. If you play a lot of golf they are about the same as green fees for 2 rounds a week.
I've played for quite a while but would give it up without my club.