Fill a large pot with lightly salted water and bring to a rolling boil. Stir in rotini and return to a boil. Cook pasta uncovered, stirring occasionally, until tender yet firm to the bite, about 8 minutes. Drain and rinse with cold water; set aside.
Whisk mayonnaise, vinegar, garlic, salt, and black pepper together in a large bowl until combined. Stir in basil.
Stir in rotini, tomatoes, bell pepper, and olives gently until combined. Chill in the refrigerator for 3 hours to overnight. Stir gently before serving.
