Cook pasta in large pot of boiling water until tender but still firm to bite.
Meanwhile fry the bacon over medium-low heat in a 12-inch skillet until crisp, about 3 to 5 minutes. Transfer bacon to paper towels to drain.
Peel and coarsely chop the onion. Add to the skillet along with the wine, garlic and Italian seasoning. Stir to loosen the brown bits from the bottom of the skillet. Increase the heat to medium and cook, stirring from time to time, until the onion is tender, about 2 to 3 minutes.
Crumble the bacon into bits, using a knife if necessary. If using the parsley, chop finely.
Add shrimp and half-and-half to the skillet. Stir well and cook just to warm through, about 1 minute. Do not boil. Remove the skillet from the heat.
Drain pasta. Return pasta to the cooking pot (removed from the heat). Pour the shrimp mixture into the pot with the pasta. Add the bacon and stir.
Serve at once, garnishing each plate with 1 tablespoon Parmesan cheese (or more to taste) and a little chopped parsley, if desired.