In a large, deep skillet, cook the onion in the oil over medium heat, stirring, until golden brown, about 10 minutes
Add the curry powder and cook, stirring, for 30 seconds. Stir in the tomato juice, wine, and chutney and simmer for 2 minutes to blend the flavors.
Remove from heat and stir in the chicken. Transfer to a large bowl and refrigerate until chilled.
Toss the chicken mixture with the celery, red onion, mayonnaise, ¾ teaspoon salt, and ¼ teaspoon pepper. Fold in the grapes and spinach.