OYSTERS AND white wine can be the ingredients for a simple luncheon or appetizer or an elegant first course. The wine can set the tone and the oysters -- whether on the half shell, stewed, mornay or Rockefeller -- will play back the theme. For this duet to succeed the wine must be dry and tart. The tartness of the wine, like that of lemon juice, brings out the flavor of the oysters. In general, wines with citrusy or slightly earthy aromas go better with most oyster dishes than do wines with floral aromas.

In today's wine market there are enough good wines from California, Burgundy, the Loire Valley, Alsace, Spain and Portugal to provide any lover of oysters and wine with a vast spectrum of combinations that range from earthy to rich and sophisticated.

Decent, though not always dependable wine can be had for less than $4 a bottle. Compared to the well-made, relatively complex $5 and $6 bottles available, however, the cheap wine is no bargain. If you are willing to shell out $5 or more, you can get good value for your money.

For less than $4 you can buy Blanc de Blancs, non-vintage (NV) by Lamblin & Fils and Blanc de Blancs, NV, by Armand Roux; both sell for around $3. Moreau Blanc, NV, by J. Moreau & Fils is a bit more. The quality of these low-cost blends varies from lot to lot.A good bottle can make pleasant drinking; a poor one may contain some off flavors.

Cotes du Rhone Blanc, 1978, by Jacques Millar, is steely and clean, with some earthiness. Portuguese Vinho Verde, NV, by Aveleda, about $3.75, is light, simple, tart and low in alcohol. It has a slightly vanilla nose and is very drinkable. You could drink any of these wines with hot oyster dishes but more complex preparations deserve to be played against more complex wines.

For $5 to $8 you can get some very fine wines that are complex and finely balanced and that show good varietal characteristics. The flavors and aromas of these wines can highlight component flavors of the shellfish dishes and each of them is tasted in the light, as it were, of the other. Most of these wines will harmonize well with oysters on the half shell, as well as with more elaborate oyster dishes.

In this group are the 1979 California fume blanc, sauvignon blanc and chenin blanc wines done in the dry style. California's 1979 white wines are more acidic than those of other recent years so the oyster lover can successfully look west as well as east for his or her wines.

Many people know about the Loire's muscadet which the French have traditionally drunk with shellfish. The Loire also produces some fine wines from the sauvignon blanc grape bearing controlled appellations such as Touraine, Savennaires and Pouilly Fume.

Chateau de la Noe, 1979, Muscadet, around $5 is the best Muscadet I have tasted in a long time. It had a moderately intense, appealing nose with good varietal character, some vanilla and a hint of the sea. In the mouth the wine was fruity and cleansing with good acid, medium body and a nice finish.

Baron Briare, Sauvignon, 1976, Touraine, about $5 had a strong fruity aroma reminiscent of grapefruit with a hint of earthiness and black currents. It had a good fruity flavor, and a long, tart finish. With a medium body, it was crisp and clear.

Chateau de la Brizoliere, sec, 1976, Savennieres, around $6. This wine had a moderately intense fruity, earthy aroma, with a hint of skunkiness, which was a minor flaw. In the mouth it had a good body, was crisp, clean and citrusy. This went better with oyster stew and mornay than with oysters on the half shell.

Monopole, 1976, white Rioja wine, by C.V.N.E., around $5 had a nose that was moderately intense, complex and fruity, laced with hints of vanilla and oak. Flavor was complex with the same characteristics as the nose. It was dry, well-balanced and had a long finish. Not as tart as the others, but it had enough acid and character to set off the oysters on the half shell in a unique and intriguing way.

Sonoma County, Chenin Blanc, 1979, by Dry Creek Vineyard, around $5 had a beautiful, intense, fruity nose with aromas of grapefruit and pumpkin. In the mouth it was very dry, clean, crisp and fruity with overtones of grapefruit. It went very well with oysters raw or prepared in a variety of ways.

French chablis and oysters used to be standard partners. But with common chablis at $8 and premiers and grands crus now running $11 to $18 a bottle they are likely to go their separate ways. Champagne, too, now costs about $12 a bottle or more, though the Codorniu brut from Spain for about $6 and Domaine Chandon brut from California for about $10 are reasonable substitutes when an occasion is meant to be festive.

For those willing to spend $7 here are two wines worth the money. Pouilly Fume, 1979, by Michel Duval, has an intense sauvignon blanc nose, (flinty), with aromas of pine and green tomatoes. In the mouth it was tart, dry, fruity, earthy; had lots of character.

Mercurey, 1976, Chateau de Chamiry, Marquis de Jouvennes d'Hervilles, had a dank fruity nose, earthiness, slight pepperiness, with a hint of skunkiness (burnt rubber). This flaw was more than compensated for by the rich feel of the wine in the mouth. In fact, one of the two bottles I tasted had a beautiful soft, silky texture rarely encountered in a wine of this price. The flavor was fruity, tart, semi-crisp, with a lingering finish. This wine is not widely available and is in limited supply. I have seen it in half bottles for around $3.50 and in whole bottles for about $8 to $8.50 at Continental, A&A, and Woodley.

NOTE: A spicy cocktail sauce can overwhelm the flavors of good wine. If you like your oysters with horseradish or hot pepper sauce, the $3 to $4 wines or beer would be a wise choice.