However, since the release of vCAC 6.0 documentation, standalone vPostgres is EOA and no longer available as a standalone product.

To address customers needs, VMware developed a way to utilize the vPostgres instance located in the vCAC appliance in a HA mode without having to incur additional licensing costs.
This KB article provides information on setting up streaming replication using an instance of vPostgres located inside the vCAC Appliance.