Perhaps this amount should instead be 250 (because the email confirmation gives 50 rep). I ran into a user who has >2k rep on A51 and he didn't give the association bonus to his other two accounts (which are at 1 rep).
Shouldn't Area 51 account, when reaches 200 rep, give assoc if you have another accounts?
Area 51 simply isn't your casual Stack Exchange site. It is completely different and works differently on all points. On other network sites, we judge that if you reach that number of reputation, you should be able to use basic functionality on other similar sites since the overall functionality are the same.
In other words, Area51 doesn't give you any experience in using regular Stack Exchange network sites.