I was in there today using my $5 off Certificate that I got in a mailer a couple of weeks ago. (Lunch was $1.50 after I chose a $6 pizza!), and I saw the sign for free tea on July 29. I didn't see any exclusions besides that it isn't applicable on catering gallons of tea.
They also have kids eat free every Saturday.
3335 College Park Drive
The Woodlands, Texas 77384