Spectacular Bid can set a record for earnings in a season by winning the $367,000 Meadowlands Cup tonight. But when he does it there should be a small asterisk placed next to his figures in the record book.

At least, there ought to be some way to indicate for posterity when a horse has earned money and victories honestly and when he has been handed them on a platter. The distinction is become increasingly important in American racing. It is now commonplace for a track to set the purse money, the weight assignments or other conditions of a race for a single horse's benefit.

Its is a matter of simple economics: race tracks want box office attractions that will increase their business, and will pay for them if necessary. The Meadowlands paid jockey Steve Cauthen to come from England to New Jersey for one night of riding this fall. And they had paid, albeit indirectly, to get Spectacular Bid to their track.

Harry Meyerhoff, the colt's owner, negotiated with track officials, who offered to raise the purse of the Meadowlands Cup by $100,000 to entice him. Then trainer Bud Delp said he wouldn't run Bid if he had to carry more than 126 pounds.

Because the Meadowlands Cup is a handicap, racing secretary Eual Wyatt was supposed to assign weights that would theoretically equalize the horses' chances, or at least prevent the race from being a run-away. Did Wyatt peer deep into his soul and announce, "I cannot, in good conscience, assign the second-best horse in America a ridiculously low weight even if it means keeping him out of our race"? He did not. He assigned Spectacular Bid 126 pounds.

Bid's principal rivals tonight, the 3-year-olds Valdez and Smarten, are being asked to carry 121 and 120 respectively. This is ridiculous. A month earlier, when New York's Lenny Hale was assigning weights for the Marlboro Cup, he would have had Bid conceding the same colts eight pounds, but now that Bid has won the Marlboro by five lenghts and run brilliantly against Affirmed. Wyatt thinks he now needs to give less weight to Smarten and Valdez.

Wyatt's weights were a blatant gift for Spectacular Bid the sort of gift that big-name horses have been getting frequently during the last few years. The trend began when Secretariat became and equine celebrity, with his picture on the cover of all the national magazines, and every race track knew that he would be a tremendous box office lure. So Arlington Park arranged a laughable, pointless race for him against three nonentities and owner Penny Tweedy sent Secretariat to the Midwest to pick up the easy money.

Seattle Slew was often the beneficiary of race track largesse. After he won his Triple Crown, Hollywood Park paid his owners to send him West for one of their big races. The next winter, Slew went south because Hialeah offered to create a special race for him.

The next Triple Crown winner, Affirmed, got his share of special treatment too. He became the first $2 million thoroughbred because the purse of the Hollywood Gold Cup was jacked up to $500,000 especially for his benefit.

To the purist, these special favors for big-name horses are appalling. Horses ought to be campaigned the way Forego was, running only in the toughest races, shouldering whatever weight the racing secretaries imposed, with his owner asking for no favors. Doing it the hard way did not stop Forego from winning $1.8 million.

Happily, the gods who oversee horse racing seem to reward such virtue. The lure of easy money in trumped up races often backfires on horses' owners.

Secretariat's journey to Chicago, coming shortly after his tough campaign in the Triple Crown, knocked him out physically. He suffered a stunning upset in his next start.

Seattle Slew was trounced in his ill-advised race at Hollywood Park. Then when his trainer tride to get him ready for the easy pickings in Florida, he pushed him too hard, too fast, and the colt was not able to race for months.

Such travails probably are not going to befall Spectacular Bid just because he wins some easy money tonight. But his admirers hope that Meyerhoff and Delp won't keep the colt in the path of least resistance during his next year of racing. Spectacular Bid does not need any track owner's or racing secretaries' generosity to compile a great record.