Coarsely chop shrimp. Place shrimp in small glass bowl. Pour wine over shrimp; toss to coat. Cover; refrigerate at least 1 hour to blend flavors. Drain shrimp, reserving wine.
In another small bowl, mix cream cheese, mayonnaise, 2 tablespoons of the onions and the mustard with spoon. Fold in shrimp. If a thinner consistency is desired, stir in small amount of reserved wine.
Line small serving bowl with Bibb lettuce. Spoon shrimp spread into bowl. Sprinkle remaining 1 tablespoon onion over top. Serve with crackers.