Hi John,
This applies to a Word Processing document in Pages.
Here is a screen shot of Text Boxes surrounded by text. The Text Boxes are floating and Wrap is set on (Inspector > Wrap > Object causes wrap).

Click on one Text Box to select it, then Menu > Edit > Select All (command a). That will select all Text Boxes but not the body text:

Try clicking in the body text, then Select All. That will select all the body text but not the Text Boxes. Clever!
The Text Boxes must be floating. If they are inline, and wrap is turned off they will behave as large 'text' characters within the body text and will be selected along with the body text.
Thank you for your question. I just learned something.
Regards,
Ian.
Message was edited by: Yellowbox. added 'and wrap is turned off' (I just learned something more).