No começo, eu queria muito dizer não, você não pode fazer isso, mas pensando bem, vá em frente.
"“You must register the Kerberos service principal names (SPNs), the host name, and the fully-qualified domain name (FQDN) for all the new DNS alias (CNAME) records. If you do not do this, a Kerberos ticket request for a DNS alias (CNAME) record may fail and return the error code KDC_ERR_S_SPRINCIPAL_UNKNOWN.”
For follow up I can confirm that the kerberos connection is established correctly. Thanks for the link as it confirms that only a CNAME is needed as long as the SPN is created for the SQL Cluster Name.
Technically, because SQL Server SPNs include an instance name (if you are using the second-named instance on the same computer), you can register the DNS host for the cluster as a CNAME alias and avoid the CNAME issue described in Appendix A, Kerberos configuration known issues (SharePoint Server 2010). However, if you choose to use CNAMEs, you have to register an SPN using the DNS (A) record host name for the CNAME aliases.