The District's home rule powers were strengthened yesterday when the Senate passed and sent to the president legislation that has the effect of cutting in half the time Congress has to review actions of the D.C. City Council.

The legislation, which has passed the House in May, sets the time during which Congress may veto a Council bill at 30 calendar days, excluding weekends holidays and recesses of more than three days. The old language counted only those days when both houses were in session toward the 30-day period, which had the effect of extending the review period to about 60 calendar days.

Councilman Dave Clarke called the congressional action "an improvement, nothing that under the old wording "we had a horrible time trying to estimate when our legislation would take effect."

At its worst, under the old wording it took seven months for the Condominium Act of 1976 to become law. The unpredictability of the old language led the Council to enact what the Congress found to be "an inordinate amount of temporary (30-day) 'emergency legislation,' "that required no congressional review and took effect immediately.

Other sections of the amendment to the Home Rule Act of 1973 approved yesterday give the Council an additional 13 days to review the mayor's budget request; eliminates authority for the president to veto action that the Council has adopted by two-thirds vote over the mayor's veto; gives the mayor pocket veto power of bills passed council 10 days prior to adjournment (although Clarke said as a practical matter the council never adjourns); and treats ballot initiative referendums the same as council legislation by making them subject to congressional review.

Meanwhile, the Department of Transportation continued its efforts to find a compromise that would a settle the Union Station/National Visitor Center question.

The House Public Works Committee wants to keep the trains out of the Visitor Center, which now occupies all of what used to be Union Station, and finish the work on a parking garage and related road facilities. Trains now operate out of a small, new terminal immediately behind the grand old station.

The Senate wants to return the trains to half of the old Union Station, restrict the Visitor Center to the other half, and add an inter-city bus terminal. Even if a compromise can be struck, there is some question as to whether Congress will have time to complete action before adjournment.