This would minimize the attack surface, however as other posters told - it is "security by obscurity" which could be one part of your defense line but not the only part.
The reduction of attack surface is only working if its a virtualhost otherwise the attacker and theirs scripts will find our phpmyadmin installation when scanning all IPs with /phpMyAdmin appended.
You could also change the default port from 80/443 to some random Port to further reduce the attack surface and minimize the change simple scans will find your phpmyadmin installation.
- invest time in a IP whitelist
- use a direct VPN to your server
- or an SSH tunnel
Most important: Do Software Updates and choose long/secure passwords.
As you mentions HTTPS. This is for encrypting your traffic so no one can eavesdrop your connection. This itself does not make phpmyadmin more secure!