Yesterday it was buses, not limousines: The participants in the inaugural social drama had to get where they were going fast, and together. The family of George and Barbara Bush, 130 strong, required four buses. Some buses served lunch -- with one fleet providing chocolate-dipped, liqueur-marinated strawberries as dessert. At the John Sherman Coopers in Georgetown, over 100 guests on their way home from the day's festivities had choice seats on the balcony for the fireworks display that set off the night's celebrations. For the GOP, yesterday was prelude to an evening of balls. But for the Democrats -- including former vice president Mondale, who was home by midafternoon -- the postlude had already begun .

As the man in the morning coat got out of the long black limousine, a large dog bounded up to greet him. "Blossom's getting fat," said the man who only 90 minutes earlier had been vice president of the United States.

Fritz and Joan Mondale had moved back to Cleveland Park house they left four years ago and the same neighbors and friends who had sent them off with ruffles and flourishes piped them back on board with a "Democratic Soup and Sandwich" lunch arranged by Ellen Bates, next-door-neighbor and Blossom's owner.

"Next time you wear that," said one neighbor of Mondale's garb, "I want to be there." The meaning was clear to everyone, especially the woman sporting a Mondale '84 button.

"Last night we didn't get much sleep," Mondale told a clutch of people on the sidewalk. "Last night was my night to stay in the Lincoln bedroom. I got Joan there about 8 o'clock. We had a private dinner with the Carters. They brought in the Marine Orchestra and we danced in the private dining room upstairs." But after dinner Carter and Mondale went back to work on the hostages. "I didn't even lie down," he said.

What kept them up was "a whole range of technical and legal problems. Every time we got one of those difficulties straightened out, another one would pop up. We worked like dogs all night. First thing you knew the sun was coming up."

Mondale said "it is not important" whether or not the Iranians were stalling in order to deny Carter a chance to greet the hostages while he was still president. "What is important is that the hostages are coming home. I think we performed a service for the Reagan administration," Mondale added, raising his voice slightly over the dogfight Blossom was having with a black neighborhood dog.

The sign on the Mondale steps, "Fritz's Bakery reopening same management (and office and budget, too)" was a reference to his earlier attempts at baking which resulted in at least one loaf seeing service as a doorstop.

Mondale may not have much time for baking or cooking in the next four years. He will be teaching in Minnesota and is expected to practice law with a firm that has both Washington and Minnesota offices.

His future plans? You can get Mondale '84 buttons from one of the women working in his transition office.