Whisk together mustards and wine. Pour over chicken; cover, refrigerate and marinate 24 hours.
To prepare salsa combine grapes, pine nuts, red onion, green onion, parsley, oil, vinegar and sugar; mix well. Season with salt and pepper.
Preheat grill.
Season each chicken breast half with salt and pepper.
Grill or broil chicken until firm and juices run clear, 8 to 10 minutes, turning once.
Plate chicken and top with 1/2 cup grape salsa.