ClearPass doesn't allow specific services to be bound to a specific service (Guest, Policy Manager, Insight).
What you could do is put the default page to the ClearPass Guest Application Login:
If your users go to guest.company.org, they will end up on the /guest. Admins can go to clearpass.company.org/tips/ to get to the admin page.
BTW, going to clearpass.company.org/ would get you to guest as well, similar to guest.company.org/tips/ will get you to the CPPM login page.
You can use (recommended to do so) Application ACLs to limit who can access what parts of ClearPass. At least prevent guests or operators to access the /tips/ part.