The 9th is augmented (or sharp) in a 7+9 (R, 3, 5 b7,#9) but is different from an Aug triad (R, 3, #5).
In the 7#9 you are getting distinct dissonant flavors off the M7 interval between the 3 and the #9, whereas in the Aug, it is much more subtle, more like an ambiguity of its tightly wrapped ball of maj and minor 3rds. Aug is frequently a passing tone because it wants so much to resolve one way or the other... while Sharp 9 says "I 've broken free and am going THIS way!"
"There, in huge black letters, was 'The Grateful Dead'. It just... cancelled my mind out."-Garcia