A White House communications decision last week, the day after President Reagan's Middle Eastern initiative, simultaneously demonstrated the administration's sagacity and the vulnerability of its secretary of labor, Raymond J. Donovan.

Donovan had been scheduled as the guest on the CBS Sunday news program, "Face The Nation." The administration offered Secretary of State George P. Shultz as a substitute, accomplishing the dual purposes of focusing attention on the president's generally popular peace plan and keeping it away from the embattled and political unpopular Donovan. Doing what any other news organization would have done under the circumstances, CBS snapped up Shultz.

Though Donovan will make Labor Day appearances on all the networks today, the switch to Shultz was another confirmation that high-placed White House advisers recognized the heavy political baggage Donovan is carrying through the midterm election. He is virtually unwanted as a campaigner for any Republican candidate, except in the safest of safe districts. He has almost no personal relationships with the leaders of organized labor. While he is personally well-liked by many in the administration, even some of his supporters acknowledge that Donovan has spent so much time defending himself that he has failed to master his job.

Donovan's foes within the administration have given up any hope of dumping him immediately. President Reagan tends to stick by his appointees, and he is known to share Donovan's belief that he has been fully vindicated after a long and painstaking investigation.

"You can't ask someone who has been through all this for 20 months to sit on the sidelines during the campaign," says one administration official.

But Reagan's political strategists are not exactly eager to have Donovan charge out on the playing field. They consider him a disappointment, all the more so because of Reagan's effective appeals to blue-collar workers during the 1980 campaign. On a Labor Day campaign swing two years ago, in Donovan's home state of New Jersey, Reagan paid tribute to the late George Meany, and said: "I pledge to you in his memory that the voice of the American worker will once again be heard in Washington."

It is an unkept promise that even some ardent Reaganites recognize could come back to haunt the administration and the Republican Party in November.

In the favorable political climate created by the mideastern initiative, deputy chief of staff Michael K. Deaver recognized that Reagan could do more for himself by awarding the medal of freedom to special ambassador Philip C. Habib in the White House than he could by campaigning for conservative GOP Sen. Orrin G. Hatch in Ogden, Utah. So Deaver changed the schedule, and Reagan will fly back to Washington tomorrow instead of stopping off at Ogden. Reagan will keep his commitment to Hatch on the lesser news day of next Friday . . . The schedule switch irked television operatives, who were already preparing facilities for the speech in Ogden, and irritated even more White House spokesman Larry Speakes. No one bothered to clue Speakes in on the change.

When Reagan departs for home, he will have spent 98 days of his presidency in California, including all or part of 77 days at his beloved Rancho del Cielo. Reagan will pay about $1,370 in taxes this year on his 688-acre ranch in the Santa Ynez Mountains, about $10,000 less than he would pay if the land were in normal agricultural zoning. The tax break is the result of the special "agricultural preserve" zoning that had been applied to the ranch when Reagan bought it in 1974. He has maintained the zoning by allowing the grazing of a few cattle on the property each year. Agricultural preserve is a tax-saving device that protects many large rural landowners in California and has been liberally applied to a half-million acres in Santa Barbara County alone.

With the timely assistance of White House counselor Edwin Meese III the administration has come up with $210,000 to reimburse Santa Barbara County for security expenses extending through 1984. The money comes from a leftover grant of the now-defunct Law Enforcement Assistance Administration. It may well be the last such grant ever dispensed, since any surplus LEAA funds will revert to the treasury at the end of the fiscal year, Sept. 30.

When White House spokesman Speakes called Philippine strongman Ferdinand Marcos "Fernando" during an announcement of his forthcoming U.S. visit, The New York Times' Howell Raines shot back: "That's a capital offense in the Philippines" . . . Reagan's best quip of the week was delivered at the NBC studios in Burbank Wednesday as technicians were preparing for the president's nationally televised Middle Eastern speech. Suddenly, assuming a presidential pose, Reagan stared into the camera and announced, with a completely straight face: "Welcome to Death Valley Days."