Kathryn Crosby says the new all-amateur Bing Crosby Golf Tournament has attracted so much interest among corporation executives, politicians and celebrities that two separate one-day events are being added to the agenda.

In an interview with the Macon (Ga.) Telegraph & News, the widow of the late entertainer said chief executives of corporations and one playing partner will participate in an 18-hole event next year on Tuesday, June 3, and the following day the nation's 50 governors will play in another 18-hole event.

The format for the tournament itself, which begins June 5 at Bermuda Run near Winston-Salem, N.C., will be a 72-hole event with full handicaps, involving two-person teams from each state and from 50 corporations.

A clambake is scheduled for Wednesday night and Crosby said President Reagan has indicated he will attend to present the President's Cup to the winning team in Tuesday's 18-hole event. She also said former presidents Richard Nixon, Gerald Ford and Jimmy Carter are expected to participate in the tournament in some fashion . . .

John Mahaffey shot a five-under par 66 to pull into a tie with veteran George Burns at 201 for the 54-hole lead in the $400,000 Bank of Boston Golf Classic in Sutton, Mass. Burns had a 68 . . .

In Portland, Ore., Beth Daniel and Stephanie Farwig shared the lead at two-under 142 after the second round of the $175,000 Portland Ping Golf Championship.