Business and politics turned out to be top subjects for local arts folk -- administrators and artists -- yesterday afternoon at the National Gallery of Art.

Joan Mondale, wife of the vice president, told the crowd of several hundred attending the third annual meeting of the Cultural Alliance, that they would have to increase their visibility on the Hill for funding.

The Alliance, a membership service organization for Washington-area arts groups, gave Mondale an award for her support of the arts.

"It's going to be very important for us to aggressively make new friends, to educate people," said Peggy Cooper, chair of the D.C. Commission on the Arts, during a panel discussion on arts funding.

"The transition has shown the doors are open -- at least ajar," she continued. "It's up to us to put some oil on the hinges to make the doors very open. If legislators have a reasonable approach to the arts and life -- civilization -- in Washington, there will not be a leveling off of funding."

In response, Kennedy Center board member Henry Strong, moderator of the panel, said with a grin, "Being a Republican, I'm distressed to hear you think we have to be tamed."

Alliance Executive Director Peter Jablow noted that a new Alliance project -- a central ticket booth, selling tickets for large and small local performing organizations, some at half price on the day of performance -- is likely to be operating by mid-1981.

On the business side, said Leonard Fleischer, senior adviser for arts programming for Exxon, "there's good news -- the arts are receiving a larger piece of the philanthropic pie."

But one question from the audience on how to persuade a company to contribute to an arts group "when they say, 'We've already contributed to the United Way -- or to the Cultural Alliance,'" underscored the fact that groups still have problems getting funding from corporations.

"The process of educating corporations with no previous involvement in the arts is a long one," Fleischer said. "There's no 'open sesame.' It's a matter of identifying people who might be sympathetic to your cause."

He offered some suggestions for getting business people involved:

"Having a party will bring people out even if they're not interested in the arts. If you have wine and cheese, people come. If you have a star at your party," he said, as listeners chuckled, "really, that helps."