Show View Pane in Node Template based on Taxonomy Term
Ok, I finally figured it out!

To show a view in a panel where the view and panel are related by a taxonomy term (in my case Team Term (field_team_term), do the following:


Use the view content panes module to create a view content pane (How can I show a view in panel with argument in Drupal 7).
In the view content pane use contextual filter "Has Taxonomy Term ID". When Filter Value is not available: Hide View. When Filter Value is available - specify validation criteria - choose taxonomy vocabulary - Filter Value Type: Term Name converted to Term ID. (Some writers suggested checking the "Allow Multiple Values" box at the bottom of the window under More; I found that unnecessary.)
In the Pane Settings - Argument Input, select "From Context". 
Under Required Context, select Name under Taxonomy Term.


That completes the views setup.

In the panel settings, 


Set up a relationship"Taxonomy term from Node (on Node: Team Term [field_team_term])" in the case of my taxonomy term field.
In content, add the view pane, and select the taxonomy term relationship as the argument.


As near as I can tell, that is only combination of panel context and view arguments that will get the job done. I hope this helps someone.