Organic Groups Create Content Link does not appear
Not sure which permission you mean with the "Permission to create content for content type is set" (consider adding the URL within admin to clarify that, is it /admin/people/permissions?).

However, it could well be that your issue is because you've not yet completed the "OG Permissions" located with something like /admin/config/group/permissions/ (and then select the 'edit' link for the group type your issue is about).