Something to note is that unless the leaders of the coven literally click, "reject" on your application then in order to apply to another coven you have to manually remove your own application.
To do this, go back to the coven's page that you applied to, click "Accepting Applications", then click "Remove your application from (whatever the coven's name is)."
This will remove your application from the coven, and make you immediately able to apply to another coven.
You don't have to wait to apply to another coven, if you follow the steps I wrote for you, you can technically apply to an unlimited number of covens in one day. But keep in mind, once you remove your application from a coven, they cannot accept you, therefore you cannot join multiple covens on one account.