The Democratic-controlled House yesterday approved a pared-down $10.9 billion transportation spending bill for next year in the latest example of give-and-take between Congress and the White House to avoid once-threatened veto confrontations.

The action came as a similarly whittled-back $7.6 billion Interior Department appropriation remained mired for a second day in a Senate dispute over whether Congress should get involved in the recent bond default of the Washington Public Power Supply System, largest of its kind in American history.

A proposal to allow the Bonneville Power Administration to back nearly $1 billion in bonds to complete two nuclear reactors that were not involved in the WPPSS default was approved by the Senate Appropriations Committee.

But it ran into trouble on the Senate floor when Sen. Howard M. Metzenbaum (D-Ohio), calling the proposal a back-door bailout for the troubled power system, challenged it on procedural grounds as well as substantive grounds.

Sen. Slade Gorton (R-Wash.) argued that, while the system has authority to issue new bonds for reactors not involved in the default, it can't do so because "no one will loan it any money at this time." The proposal would allow the Bonneville Power Authority to back bonds issued by a separate entity to complete work on the two nearly completed reactors.

Rather than face a potentially embarrassing loss for Sen. James A. McClure (R-Idaho), floor manager for the bill and a key supporter of the WPPSS proposal, the Senate Republican leadership put the bill aside for a day, perhaps longer.

The transportation bill, which awaits Senate action and resolution of one or two remaining differences, will be the fourth of the 13 regular appropriations bills for fiscal 1984 to go through Congress, most of them with an advance nod from the White House after a series of mutual concessions.

The other three bills, providing funds for the legislative branch, for energy and water projects and for the Department of Housing and Urban Development and 17 independent agencies, have been signed into law. A $7.1 billion supplemental money bill for the remainder of this fiscal year, ending Sept. 30, was also approved and signed after Congress shaved it back to keep the measure within limits set by President Reagan.

No appropriations bill has been vetoed this year, although congressional leaders note that some of the biggest and most controversial are still to come.

After Congress approved budget targets that he opposed earlier this year, Reagan vowed to veto individual spending bills that conflicted with his own priorities, and some Democrats welcomed the prospect of a fight over politically popular programs.

But so far, even the Democratic House has tried to pass bills that Reagan could sign, Speaker Thomas P. (Tip) O'Neill Jr. (D-Mass.) said yesterday.

"There's no sense of going to the routine of sending things over to the White House that are going to get vetoed," he commented.

The transportation bill, as revised last month by a House-Senate conference, exceeds Reagan's request by $18.7 million but drops $367.7 million from the original House version.

It was approved by voice vote of the House after members refused to go along with one House-Senate conference provision, sought by Sen. John G. Tower (R-Tex.) to earmark $25 million for work on the Houston airport. This will have to be resolved before the bill can be completed and sent to Reagan.