Unlike the other platforms we support domains that are hosted on Amazon S3 should be pointed with CNAMES to the Public DNS name.
What needs to be done is to point the the domain ot the Registrat's default name servers. This way the domain can be controlled from the registrar's DNS zone.
The next step is to add a cname for www that points to the Public DNS name and a cname for @(the domain itself) that points there too.
Some registrars do not allow CNAMEs for @. The solution is to redirect the main domain to the www. version and point the www to the Public DNS name.