Rendered node display for anonymous users? I would like to use a view field (node reference to an og group, configured to display a teaser) as rendered node inside a view and display the view to anonymous users. 
Do you know how to achieve this result ?

PS. Currently I can display it for admin user but for non-admin users the view field doesn't appear.
If it is working for admins, but not for non admins, you problem is most likely permission. Do the users have permission to see the node? Maybe they need a special permission to see nodes via relationships?

To fix this, you need to tweak your permissions.

If you want to change the way a field is rendered, either on an entity or in a view, you need to create what's called a field formatter, which essentially is a theming function for fields.