Thanks Jorge. Sorry for "venting"...
Where I got lost was finding the right username and password to login to PhpAdmin. Eventually I found the combination I was looking for which is "root" and the password printed to the hard-console screen in the Virtual Appliance.
I think some of the complexity comes from - some people build an OS and "install" the bitnami appliance on to the system - others like me - prefer to pull down an entire VM. Couple to that there are libraries of VM on public clouds - which in turn have their own methods for handling the dynamic creation of passwords. I noticed on AWS many bitnami appliances boot-up and you find the password within the AWS Logs...
This page - https://docs.bitnami.com/virtual-machine/components/phpmyadmin/
Leads to this page - https://docs.bitnami.com/virtual-machine/faq/#how-to-find-application-credentials
If you read it closely its quite clear - I just didn't "see" it...
It might be handy to have single page where all the credentials are listed?
It would be hand to have a list I what cannot and cannot be done next to the accounts. So bitnami can SSH if SSD is configured, but root cannot without editing sshd_config. Neither bitnami/root are valid to login to Mediwiki to author content - but user does.
I assume this console generated password exists in a log file somewhere. I don't know about others but long complex password which use a mix of cases are easy to get wrong dependent of character font used. I can't be the only one to struggle to see the difference between i L l I (those last two characters one is a captial i and the other is lower-case L). Being able to SSH as bitnami, copy the password for user/root to the clipboard to be pasted into web-pages, SFTP clients and so on would reduce potential errors...