Hi Jacob,
Thanks for your response about the plugin, after you reported that it was not working I’ve done my share bit of testing and I see that It doesn’t work as expected, sorry for setting you on the wrong path.
From what I tried no plugin will deliver the results you are expecting, so I will give you a solution that might solve the problem but it’s not what you asked for;
You can try to use the Restrict Content Pro from PippinsPlugins, which will allow you to give certain users and roles access to individual posts, it won’t be by taxonomy but it’s a start.
Hope this kinda solves your issue, because that’s as far as our support can go on a custom modification complex as this one.
Sorry if I wasn’t able to help you.
My Best Regards,