A plan to liberalise American policy for admitting foreign Communist visitors to the United States now awaits White House action - and beady looks from another decision center a few hundred yards noth on 16th Street.

Administration insiders are privately wagering among themselves whether President Carter, publicly committed to greater freedom of travel or determined AFL-CIO President George Meany, will prevail. The odds appear to favor Meany.

For years the labor federation has virtually exercised a veto over the admission of Communist trade unionists to the United States on trade union matters. The official euphemism is that no such veto right exists, but that the government, among other things, takes cognizance of "the attitudes of the mainstream of American labor."

The "mainstream of American labor" always says no on entry visas for such Communist trade unionists. The AFL-CIO position is that free trade unions do not exist in Communist nations, and that so-called Communist trade unionists are actually government officials. In the past, the administrations in power always have concurred with the AFL-CIO stand. But there has been growing official discomfort over the distinction between Communist trade unionists and other Communists who increasingly have been granted visa waivers to enter the country.

In confirmity with President Carter's commitments to human rights, and freedom of travel, the Carter administration last month removed restrictions on American travel to Cuba, Vietnam, Cambodia and North Korean. The President also told the United Nations on March 17 that in additon, "we are moving now to liberation almost completely travel apportunition to America."

That is the purpose of "what is described as "a broad-scale review of the problem of political affiliation" now awaiting the President's decision. The trade-unionist issue, a White House source said yesterday, is only relativety small part of the pending review.

But it is the most roublenome, potentially embarrasising issue awaiting the President's decision, other sources say.

"I can't think that Carter is going to want to take on Meany on this issue," said one source. "He has too many problem with Meany now."

The AFL-CIO, dismayed by the number of Carter decision that have gone against it, publicly exploded against the Carter administration on April 4. The immediate cause of the AFL-CIO leadership charge that the President had failed to keep his primises to the "working people" was Carter's rejection of high tariffs on shoe imports to protect American industry.

By comparison, the visa issue is insignificant. But defying Meany on that long-standing ideological dispute, some insiders believe, might, send the AFL-CIO leadership "irretrivally over the edge" with the Carter administration. Megny has told both the President and Secretary of State Cyrus R. Vance that the visa bairer is very important to him.

Up until now, the Meany position has prevailed through continuance of the old policy, while the State Department completed the policy review that is now before the National Security Council staff.

On Saturday, the State Department refused to seek visa waivers, required under the McCarran-Walter immigration and Nationality Act of 1952, to permit three Soviet trade unionists to enter the United States. The request for waivers came from the International Longshoremen's and Warehousemen's Union headed by Harry Bridges, who is now planning to retire after a lifetime of labor militancy.