I’ve given bors permission to all the repos of gfx-rs organization, and I can approve any of them AFAIK. However, bors doesn’t recognize my status on metal-rs, which was moved in (IIRC, after I initially set bors for gfx-rs).
You can trigger a sync yourself. It’s bound to the “Sync pull requests” (I should probably change the label) button.
It is triggered when a repository is added, but it isn’t run on a timer or anything, so if you add or remove admins it won’t automatically sync them. That probably counts as a bug, too.