The administration's foreign aid bill was sent to the House floor by a one-vote margin in the Rules Committee yesterday amid predictions that its days are numbered.

House members in both parties and of various persuasions were lining up to get their licks in on one of the year's most unpopular pieces of legislation, which includes increased aid to El Salvador.

"It will be a disaster," said Rep. William S. Broomfield (R-Mich.), the Foreign Affairs Committee's ranking Republican who will support it in what he regards as a hopeless cause. "It will be like raw meat hitting that floor."

The 5-to-4 vote of the Rules Committee came after several members questioned the wisdom of submitting it to a predicted slaughter this early in the year. The House leadership intends to bring it up next week.

A supplemental authorization, it contains money for this fiscal year for Egypt and Israel, more aid for El Salvador, and a renewal of assistance for Argentina and Chile.

The mood is considerably different from that which prevailed last year when a fragile alliance was patched together to pass the Reagan administration's first measure. It worked then because some conservatives who habitually vote against foreign aid were encouraged to support a package substantially increasing military assistance.

That appeal now has been overcome by recession and unemployment. "With the economy in this bad a shape, they're not going to pass a foreign aid bill with all that military money in it," Broomfield said.

Disenchantment with some of the proposed aid recipients also makes passage doubtful. Rep. David E. Bonior (D-Mich.), a member of the Rules Committee, said yesterday he would speak against the bill because it contains too much money for what he called "repressive governments." It would be the first time Bonior has ever opposed foreign aid legislation.

The bill carries $60 million in military aid for El Salvador, compared with $26 million voted last year, and comes to the floor as support for that country is diminishing. A new Salvadoran government's suspension of part of the U.S.-endorsed land-reform program is cited as a key reason for the decline in support.

"The leaning this year [in the bill] is more toward the militaristic," Bonior said, citing the proposed aid to El Salvador and small amounts for military training in Chile and Argentina. "Some are opposed to it just because it is spending money and some on philosophical grounds. I think it's doomed."

Rep. Butler Derrick (D-S.C.), who generally opposes foreign aid, said he had voted against granting the rule to clear the bill for the floor primarily because of the increased military aid to El Salvador. "We have become the arms merchant of the world, and that's repugnant to all we stand for," he said.

Foreign Affairs Committee Chairman Clement J. Zablocki (D-Wis.) indicated he would seek to amend the bill on the floor to put more strings on the money destined for El Salvador. A draft of his amendment, similar to part of one already attached in the Senate, would prohibit any funds for that country if it changes or suspends the land-reform program to the detriment of the beneficiaries.

Meanwhile, a House subcommittee voted to make it even more difficult for President Reagan to certify next month that El Salvador is eligible for U.S. assistance. The Inter-American Affairs subcommittee unanimously approved an amendment requiring the president to certify that El Salvador is trying to bring to justice those responsible for the slayings of four U.S. churchwomen and two labor leaders in 1980 and 1981.

The suspected killers have not been brought to trial.

A declaration by Reagan that El Salvador is making progress in social reforms and in curbing human rights abuses was made a prerequisite for the president's certification last January.