You need it to be connected to the local network at least. Pleas check network configuration. Or try host only mode - it may also work. If nothing helps - contact support team - this case worth being investigated. www.parallels.com/support
In order to connect PostgreSQL server from windows you have to configure you network as bridge mode and configure same subnet IP address as your MAC. you have o login like this 192.168.1.10[Mac ip address]:5432. It's may help..