The good thing is that you can address the negative feedback from your previous application. You have increased your GMAT score and you can re-write your essays so that your professional experience is clear.
On the flip side, there is no way to totally determine your chances at HBS or Wharton. Wharton's 50% GMAT range is 650-770 and the average GPA last year was 3.5. Harvard's 50% GMAT range is 700-760 and last year's average GPA was 3.67. So you fall within the range of scores for current students. However, admissions committees look for competitive applicants as well as diverse MBA classes. This means that your chances are somewhat dependent upon who else applies and your ability to differentiate yourself for the pool of applicants.
Really focus on creating compelling essays that communicate your professional experience and also lend insight into your personality. Try to show what you as an individual can add to the incoming MBA class as well as why HBS/Wharton is a great fit for you.