There's no published minimum GPA requirement for Wharton's MBA program. Wharton, like other top business schools, uses a holistic admissions process. While a high GPA is certainly a strong indicator and improves your chances significantly, they consider many other factors such as GMAT/GRE scores, work experience, essays, recommendations, and extracurricular activities.
Expecting a GPA below a 3.5 will likely make admission very difficult, and anything above 3.7 will improve your chances substantially. However, even a perfect GPA doesn't guarantee admission. Focus on building a strong overall application.