By Kevin Gray Millions of people flock to Austin each year for major events like SXSW, Austin City Limits and Formula 1 races, and the city has become a popular vacation destination for its cuisine, nightlife and fun-loving sensibilities. But while Austin was welcoming travelers, hotels were playing catch-up. A spate of recent openings is helping to ease the demand, including sibling properties Thompson Austin and tommie Austin, which debuted earlier this year in a shared downtown building. In addition to providing a comfortable place to spend the night, the duo enlisted a nationally acclaimed…