President Reagan won two foreign policy victories in the Republican-controlled Senate Foreign Relations committee yesterday, as the committee voted to authorize $350 million in bilateral foreign aid to Caribbean nations and to set up Radio Marti to broadcast news and opinion to Cuba.

The Caribbean Basin Initiative and Radio Marti are pet projects of Reagan, who views them as necessary weapons in the battle against Soviet influence in the area.

Actual funding for the Caribbean Basin plan is still up in the air. The funds, which include up to $100 million for El Salvador, were approved by the House yesterday as it overrode President Reagan's veto of the 1982 supplemental appropriations bill. However, the Senate must still vote on the veto, later this week or next.

The Senate committee's unanimous approval of the administration's Caribbean aid authorization was a sharp reversal of a 9-to-8 vote this spring to channel the funds through the World Bank, instead of giving them as a direct country-to-country bilateral program.

The World Bank proposal was withdrawn by its sponsor, Sen. Christopher J. Dodd (D-Conn.), after heavy administration lobbying. Dodd, who had argued that funneling the money through an international institution would encourage other countries to join in the program, feared that the dispute would hold up funding past the deadline for 1982 appropriations.

The World Bank, reportedly under administration pressure, had also informed the committee that it would be unable to set up a special fund for Caribbean nations, as proposed by Dodd.

As a compromise, the committee included a provision asking the president to work toward an increase of at least 15 percent a year in lending to Caribbean Basin countries by the Inter-American Development Bank.

The debate over $7.5 million in funds for Radio Marti was far more heated, as a substitute amendment by ranking Democrat Claiborne Pell of Rhode Island, which would have replaced the new station with expanded Voice of America broadcasts to Cuba, was defeated 11 to 5.

The United States would be "shooting itself in the foot" with Radio Marti, Pell said, because of retaliation by Cuba, which has threatened to jam the U.S. station and interfere with broadcasts of U.S. commercial stations with a 500,000-watt AM station.

Cuba is unlikely to jam an expanded Voice of America, Pell said, adding that his solution would be "less confrontational than the propaganda" broadcast by Radio Marti, named for the Cuban national hero Jose Marti.

However, the committee chairman, Sen. Charles H. Percy (R-Ill.), argued that the Voice of America's mission is to inform the world about the United States, whereas Radio Marti would be telling Cubans about Cuba and discussing such issues as "Is the Cuban system working or are they a vassal of the Soviet Union?"

Expanding VOA would hurt its credibility by making it a "propaganda agency, another Voice of Moscow," he said.

Also defeated, by a party-line vote of 9 to 7, was an amendment by Sen. Paul E. Tsongas (D-Mass.) to have the federal government compensate commercial stations for any financial losses as a result of Cuban retaliation.

The National Association of Broadcasters is lobbying against Radio Marti, because of the fear of retaliation, and objections have been raised by station WHO in Des Moines, where Reagan was once a sportscaster, and which is on the frequency originally designated for Radio Marti.

The Congressional Budget Office has estimated that more than 200 radio stations in 32 states would be threatened by Cuban interference.