Second Google Account for Phone I have a second Google email address for business.    I would also like to be able to upload business photos / media to the HOA account with photos: can this be done and how?

I have added the 2nd Google account to the phone successfully, but attempts to share photos (via Google-Photo app) presented only the one (the original) Google account.
You have to add the second Gmail account to the Google Photos app separately. You can upload photos to this account by switching to it from within the app. 

To add the account just open the hamburger menu from the left of the Google Photos app, click on the downward facing arrow next to your user name and then select the Add account option.