PRESIDENT Abol Hassan Bani-Sadr does indeed seem to be increasing his authority within the previously fragmented political structure of Iran. Using his position as the popularly elected head of state, he has become leader of the governing Revolutionary Council and has moved to isolate and weaken the militants holding the hostages in the American Embassy and to keep them from appealing over his head to the ailing Ayatollah Khomeini, still the ultimate source of power in revolutionary Iran.

What is not clear, however, is how President Bani-Sadr intends to use his accumulating authority in the matter of the hostages. Does he believe that Iran has made its point about the shah and the shah's American connection, and that it would do better now to negotiate promptly the release of the hostages and to turn to other matters -- such as the Soviet menace, ethnic unrest and economic deterioration, not to speak of the revolution's own radical program? Or does he believe that the "education" or humiliation of the United States, whichever it is, is not yet complete? A negotiated solution, involving some sort of international commission in which the revolution's complaints against the shah could be broadcast, is available to Mr. Bani-Sadr for the asking. Will he ask"

The Carter administration has now publicly put aside its former policy of tightening the screws and of asking other nations to tighten the screws in order to punish Iran for holding the hostages. It did so by way of acknowledging the new context created by the Soviet invasion of Afghanistan and the accession of President Bani-Sadr. The irony of it is, of course, that even before the hostages were seized the administration had not the slightest perceptible interest in restoring the policies identified with American support of the former shah. It did not take the seizure of the hostages to transform American policy. But it will take the release of the hostages, who have been cruelly incarcerated now for almost 100 days, for the search for any mutually beneficial and respectful relationship to begin.