Burgeoning membership and services were the Cultural Alliance's key accomplishments last year, according to its executive director, Peter Jablow, at the service organization's annual meeting yesterday.

Since its beginnings in 1978, the organization has gone from 40 charter members and 16 individual members to 500 individual members and about 250 member organizations.

The biggest success story is TICKETplace, the half-price, day-of-performance ticket booth for the performing arts located at 12th and F streets NW. Since its opening in the late fall, Jablow told the gathering at Arena's Kreeger Theatre yesterday, "We generated 80,000 new dollars in the arts and sold 8,000 tickets. In the first year of operation we project some 600,000 new dollars for the arts."

In addition, the Cultural Alliance has become an equity partner with developer Conrad Cafritz in a bid for development of the lucrative city-owned Portal Site in Southwest Washington. If Cafritz and his associates are awarded the right to develop the land, the Alliance could reap "$1.5 million a year in revenues by the 1990s," Jablow said.

Jablow stressed that the Cultural Alliance, which sees its goal as building up the cultural community here, must avoid vying with its members for funds. "In the long run," said Jablow, "we've got to get out of competition with our members for limited dollars."

About 400 people gathered at the meeting, which also included a keynote address by National Endowment for the Arts chairman Frank Hodsoll. The crowd included those who run large and small arts organizations, urban and suburban. The group was predominantly white, although some of the more active Alliance members, including about half a dozen board members, are black.

Getting minority members has "been a problem for us from way back," said Delano Lewis, assistant vice president of C&P Telephone Co., and a former president of the Cultural Alliance who is black. "We're aware of it . . . I think we've developed a trust level. There were a number of blacks in the beginning phase and we were out front. But for the fledgling black groups, they weren't sure there was something in it for them."

"I think our minority membership has grown," said Jablow, "but it still has a way to go. We had a half-dozen to a dozen minority members in the beginning. It's more than doubled since then."

Hodsoll spoke in general terms about the need to sort out priorities in arts funding and increase private sector support, two of his often emphasized themes. "I hope in the first half of 1982 to undertake two important tasks," said Hodsoll. "One, to organize a series of seminars around the country on the state of the arts in America, and two, to test different methods of providing assistance to localities in assessing a) how best to improve the arts presence in a locality and b) how best to raise money for that arts presence."

The finale of the meeting was a surprise tribute to Patrick Hayes, longtime and ubiquitous Washington arts entrepreneur who is taking temporary leave of the Washington Performing Arts Society, for his work in the city. "As my namesake, Helen Hayes, says, 'Longevity is everything,' " responded Hayes. "My advice is: Live long . . . you'll outlive all your rivals if you have any."