In a large bowl combine turkey and wild rice (room temperature or chilled), green onions, water chestnuts, and golden raisins. Optional: toss with half of the dressing and refrigerate for an hour or two before serving.
Just before serving, stir in the grapes and more of the dressing. Garnish with more green onions, etc., and fresh tarragon.
See bullet points above in post for recipe variations and options.