Remove heavy outer husks from corn; pull back inner husks. Remove and discard silks. Cover corn with water; let stand 30 minutes. (Keeps husks from burning.)
Drain corn, and pat dry. Pull husks over corn.
Stir together tea and next 6 ingredients in a small mixing bowl.
Grill corn, covered with grill lid, over medium heat (300° to 350°) 20 minutes. Carefully pull back husks, leaving attached. Brush kernels with vinaigrette. Serve with remaining vinaigrette.