security - Do permissions apply across users?

If I create a secondary user and install an app while using the phone as that user, will the permissions for that app carry over for the primary user?

For example, let's say I have a primary user, Foo, with a Google account foo@gmail.com. I then create the user Bar with the account bar@gmail.com. Whilst using the phone as Bar, I install an app with the "find accounts on the device" permission.

Will this allow the app to see the accounts I have registered with the primary account, i.e. foo@gmail.com? Will it even be able to find the primary user at all or are there hard boundaries between user "workspaces" (for lack of a better term), and as far as the app can see, there's only Bar and its registered accounts on the device?

I'm just generally concerned with apps finding out about my personal data, contacts, emails, etc, and would like to use a "dummy" account for any app I consider hostile in this regard. Would this work?

I have a Nexus 5X running Android 6.0.1.