The Fairfield Inn, a Marriot brand off I35 @ 290, used to have one, as recently as earlier this year. Plus, it has the benefit of being $5 cab ride from Sugars`
The Driskill Hotel also used to have a few rooms with hot tub/jacuzzis. High dollar space though, I am sure.
Just incidental information: The Emily Morgan hotel in San Antonio used to have suites with hot tubs, overlooking the Alamo. Sweet view at night...