The Senate Budget Committee wearied of its partisan cat-and-mouse game over spending for 1980 yesterday and voted 10 to 9 to raise Congress's budget ceiling for the year by $18.8 billion.

In doing so, the committee backed off painful spending cuts that it tentatively approved last week as Democrats and Republicans tried to outdo each other in claiming election-year honors as budget-cutters.

But even the final vote was a political statement of sorts, with two Democrats who are up for reelection this year, Sens. Ernest F. Hollings (D-S.C.) and Gary Hart (D-Colo.), joining the committee's Republican minority in voting against the spending increase.

The skirmish -- a prelude to congressional grappling with President Carter's proposed budget cuts for fiscal 1981 -- was prompted by the fact that Congress has already broken through its self-imposed spending ceiling for 1980, largely because of inflation. Without a change in the ceiling, no more spending bills could be passed for this fiscal year, which ends Sept. 30. m

In initial voting on its budget targets for next year, the committee agreed, 10 to 6, to earmark $16.3 billion for a tax cut in the balanced budget that it expects to propose for fiscal 1981.

As proposed by Budget Committee Chairman Edmund S. Muskie (D-Maine), half of the cut would come in the form of an income tax credit to offset Social Security increases and the other half would be devoted to investment incentives.

The revised spending ceiling of $566.4 billion for 1980 came within $600 million of the figure recommended by Muskie and approved earlier by the House Budget Committee.

But for a time yesterday it appeared that Muskie would not even be able to keep a majority of the Democrats on the committee from joining in a bipartisan spending/slashing spree that could have created panic in the government bureaucracy.

In one last political fling earlier in the day, half of the Democrats present at the time joined Republicans in a surprise 14-to-5 vote against Muskie's proposal for $567 billion in spending for this year.

This prompted Sen. Daniel P. Moynihan (D-N.Y.) to claim that the committee had "just destroyed the [congressional] budget process" by resisting a budget ceiling that Congress could live under. Moynihan said there was "not the slightest chance" that Congress would actually approve the spending cuts that would be necessary to keep from busting through the ceiling and thereby destroying Congress' fragile system for imposing spending restraint on itself.

After a lunch break, the committee prepared to vote on a scaled-down version of Muskie's proposal authored by Sen. J. Bennett Johnston (D.La.), but this time it was Muskie's turn to balk.

Muskie claimed Johnston's plan cut too deeply into domestic programs and withheld his support, calling for more "balanced" restraint.

Defeat of the Johnston plan could have meant victory for the Republicans in their demand for holding the line on spending and focusing cuts of more than $12 billion.

At this point, Johnston agreed to most of what Muskie wanted, with enough exceptions to let the Democratic budget-cutters claim to have made a dent in the spending total. Johnston's eventual package amounted to a $14.4 billion increase over what the committee voted last week and $18.8 billion more than the $547.6 billion spending ceiling that Congress approved last fall.