Sugar Ray Leonard returned to the scene of his Olympic glory, Montreal, yesterday with attorney Mike Trainer trying to resolve the dispute with Canadian tax authorities over his purse for his first Roberto Duran bout last June. The outcome could determine whether Montreal gets the June 1981 Leonard-Ayub Kalule bout. Meantime, said Leonard, "I'm signed to defend my (WBC) welterweight championship March 28 against Larry Bonds, the No. 6 challenger." That's the one set for Home Box Office TV, and the champ cited as leading contenders for fight site: New York, Houston, Syracuse -- and Landover, Md. . . .

Meantime, in a new venture in pro boxing, an outfit dubbed Sports Promotions Inc., headed by Gene Molovinsky and Barney Shankman, declares intent to get (another) ring revival going here with monthly cards. For starters, dates have been set at old Washington Coliseum -- yep, she's still there at 3rd and M streets NE -- focusing on determination of tristate (District, Maryland, Virginia) champions; competition March 19, May 14, June 11. And, U.S. Boxing Association title bouts are projected; initially, one for April 17. . .

Don't look for Earnie Shavers, though. The two-time world heavyweight title challenger, 36, retired yesterday, to become a partner in a nationally franchised janitorial supply business named after him.

A tennis retirement: South Africa's Greer Stevens, at 24 a seven-year veteran of the women's tour. The 1977 and '79 Wimbledon and '79 U.S. Open mixed doubles champ (with Bob Hewitt) cites "many medical problems," some stemming from a severe knee injury incurred as she returned a shot for the Boston Lobsters of World Team Tennis two years ago; and this Valentine's Day she married Kevin Leo-Smith, a farmer in her homeland. . . John Feaver, Britain's No. 4, and two countrymen in Nigeria for a tennis tournament were jailed for 16 hours in Lagos on the weekend, then deported as part of an apparent Third World blacklist of more than 100 athletes who have competed in apartheid nations. Feaver, Davis Cupper John Whiteford and Harvey Becker (former Wimbledon junior champion) had played the South African circuit in December; three Britons who had not were allowed to proceed in Nigeria. . .

A coming coaching retirement: Golden State Warriors' Al Attles -- after next NBA season, says 481-game winner Attles, telling owner Franklin Meuli he wants to reach 500 victories, then concentrate on his front office work. . .

The NBA Cleveland Cavaliers evidently aren't long for Richfield Coliseum. Owner Ted Stepien is considering Cincinnati, Louisville, Pittsburgh and Minneapolis-St. Paul. . .

Shot to death: Bruce Rhodes, defensive back for the 49ers 1976-78, outside a residence in the Bay View district near Candlestick Park in his native San Francisco. The former San Francisco State athlete's wife told police they had driven to the address and as Rhodes went up the front steps a young man ran out of the house and began firing. Mrs. Rhodes, in the car, was critically wounded. The attacker escaped. . .

The PGA Tour spices up its impending Florida sojourn: a $500,000 bonus to any golfer who wins the Inverrary, Doral and TPC next month; $250,000 for winning two of those in succession.

Commissioner Bowie Kuhn makes his annual White House visit today to present a season baseball pass to the president. Sorry, Mr. Reagan, unusable at RFK.