The Senate took another slap at President Carter's new anti-inflation program yesterday, voting to reject his proposal to step up monitoring of price increases and to repeal by mid-1981 his authority to impose credit controls.

The actions, in amendments to an otherwise-routine bill to extend the life of the Council on Wage and Price Stability, marked the latest in a series of congressional protest votes against Carter's economic proposals.

Only last week, the House defied a request by Carter to hold down defense spending and paved the way for a vote tomorrow in which the lawnmakers are expected to roll back the president's new 10-cent-a-gallon oil import fee.

Yesterday's amendments were pushed through by a coalition of Republicans and election-conscious Democrats. Sources said some senators still were angry over Carter's attempt last week to take sides in Congress' budget debate.

In its actions yesterday, the Senate:

Rejected by an overwhelming 54 to 26 a recommendation by its Banking Committee to authorize tripling the wage-price council's $9.8 million budget in order to increase price-monitoring efforts, as Carter asked March 14.

Later the Senate passed a watered-down wage-price council authorization bill by 72-11.

Approved by a vote of 44 to 39 an amendment by Sen. Bill Armstrong (R-Colo.) that would repeal as of July 1, 1981, Carter's authority to impose broad-scale credit controls as those he ordered last March 14.

Endorsed a proposal by Sen. John Heinz (R-Pa.) that would relax the current price standard by requiring the administration to use "more realistic" estimates for productivity increases in computing its guidelines.

The Senate also agreed, by a 68-to-15 vote, to cut 10 percent -- or about $20 million -- from its own housekeeping fund as part of the measure.

The amendment, by Senate Majority Leader Robert Byrd (D-W.Va.), replaced a tougher version by Sen. Harry Byrd (Ind-Va.) to require each senator and House member to cut 15 percent from his or her staff payroll.

The action on the price-monitoring budget effectively dashes any chance that Carter will win congressional approval of his proposal to beef up the wage-price council's efforts.

The House Banking Committee already has rejected the president's request to triple the council's staff, and sources say there is virtually no support among House members generally to override that panel's recommendation.

It wasn't immediately clear what practical effect the Armstrong amendment would have. For one thing, the Federal Reserve Board already has begun dismantiling the current credit controls program and is expected to finish well before mid-1981.

For another, is seems likely at this point that the amendment wouldn't be accepted in any House-Senate conference committee because it isn't considered germane under House parliamentary rules.

Finally, the Heinz proposal on the productivity estimates was regarded as mainly symbolic. The wage-price council is said to have sufficient flexibility in its guideline-setting to work around the Heinz measure.

Nevertheless, taken together, the votes yesterday constituted a visible signal of the growing displeasure in Congress over the administration's general economic policies.

Carter proposed the stepped-up price-monitoring plan as part of his March 14 anti-inflation program, which also included a tough new budget-balancing effort, the credit controls and the oil-import fee.

So far, virtually all of these proposals have run into opposition in Congress in one form or another. The lawmakers also have revamped Carter's budget priorities, voting far more for defense than the president wanted.

The full House hasn't voted on the council's budget for this year and next and is unlikely to take the proposal up until later this month. Evidence so far has been that the wageprice program isn't popular in either house.

The Senate also came within a few votes yesterday of approving a proposal by Sen. Robert Dole (R-Kans.) that would have repealed Carter's authority to deny federal contracts to firms that violate the current guidelines.

Separately, the White House announced that Carter will meet this morning with a group of 40 foot-processing executives to ask them to continue holding down their prices even though farm prices appear to have stopped declining.