Women will not be "taken seriously as a political force" until they agree to transcend political party and national lines, writer Gloria Steinem told a convention of feminist women here today.

Speaking at the concluding session of the National Women's Political Caucus' three-day meeting, Steinem said she is a feminist "before even I am an American." Without a "sense of bonding," a belief in women's ability to be autonomous, women will never achieve "power in everyday life," she said.

"Every time one person has power over another, that is politics," she said.

Steinem, who was greeted as a glamorous heroine by many of the delegates, urged women political appointees to have feminism as their first loyalty, and to "act as spies in the other camp." Otherwise, she said, "I'm not really sure that it's all that helpful to have the cream of the women's movement taken off and put inside (the system)."

In political terms, she said, women should refuse to support any candidate who isn't totally "right on the issues," such as reproductive freedom, the Equal Rights Amendment, economic parity, child care programs and job training. Furthermore, she said, women should again "march in the streets" to advance the "feminist revolution."

"It's good for the blood circulation," she joked.

"We can't approach our goal in a linear way, which is culturally masculine," she continued. "We have to do a culturally female thing and surround it."

In response to a question at a news conference, she said that President Carter is "honest but incompetent," but urged women to "stop criticizing people at the top and get out and do something yourself."

The convention, which drew more than 1,000 delegates from 47 states, was primarily aimed at urging feminists to get elected to the 1980 national political conventions. The caucus was founded in 1971 as the bipartisan political arm of the women's movement.

Former U.S. representative Bella Abzug, a founder of the caucus, has been urging women here to get elected as uncommitted delegates to the Democratic National Convention, or, where strategically realistic in states that have primaries, to pledge support to "favorite daughters," as a way of solidifying feminist support. She said that amassing a bloc of 500 feminist votes out of the 3,331 delegates at the Democratic National Convention was "not impossible."

In other action, the caucus elected 41-year-old Calfornia lawyer Iris Mitgang as president for the next two years. Mitgang defeated incumbent Mildred Jeffrey 217 to 197 after a campaign that basically pitted the East Coast against the West Coast. Mitgang is said to be more militant than Jeffrey, who has had a long career in the labor movement and is an experienced politician.