The House of Representatives is to vote today or Thursday on a historic bill that could mean $750 billion dollars in tax cuts over the next six years, a bill that will transform the way the federal government raises revenue from its citizens.

Despite this tax bill's significance, though, the fight is over it is much more political than it is substantive.

Largely in an effort to win votes, the Democrats have adopted tax changes that "no Republican member would have dreamed of a year ago," in the words of Fred Wertheimer, president of Common Cause, the "public-interest" lobbying group.

A lot of these provisions "stink," in the private estimation of Rep. Dan Rostenkowski (D-Ill.), chairman of the Ways and Means Committee that adopted them. But Rostenkowski is playing to win.

"The only question now is, who will win?" observed a senior House Democrat, who privately admitted embarrassment over his role in the tax-bill fight. Both President Regan and the House Democrat leadership have made the tax-bill vote a test of political strength, and both seem to care more about the outcome than about the contents of the bill that will be enacted.

The final tax legislation, whether it is the Democrat or the Republican version, will significantly reinforce the policy line already adopted by this Congress: to diminish federal benefits for the poor, and increase tax breaks for the relatively wealthy. House and Senate conferees are finishing work on the giant package of spending cuts that goes in the same direction.

The new tax bill also will ensure that the corporate income tax will wither further as a significant source of federal revenue, to less than 20 percent by 1986. Taxes on individual wages and salaries will provide more than 80 procent of the federal government's income.

The final product will be much closer to the Reagan program than to historic Democratic positions, but the president did not ask for its many provisions favoring special interests, particularly the oil industry.

The Republican alterative in the House would give oil companies more than $18 billion in tax breaks by 1986. Initially the new administration wanted a "clean" tax bill that would simply cut rates 10 percent a year over three years, a dream that evaporated early in the process.

For House Democrats, the issue in the tax-bill fight is preserving working control of the House. In a caucus of Democratic members yesterday, Rep. Barney Frank (D-Mass.) proposed that the Democrats allow a separate vote on provisions in the Democratic tax bill that would give $9.7 billion to the oil industry over the next five years, a proposal that particularly galls liberal Democrats.

These provisions were adopted originally by Democrat draftsmen to "buy" the votes of a dozen Democrats from Texas, Oklahoma and Louisiana, according to a member of the leadership involved in the process.

Frank's idea was rejected summarily after other liberals, including Rep. Thomas J. Downey (D-N.Y.), argued that a separate vote on oil would only hand ultimate victory on the tax bill to the White House.

If Reagan defeats the Democrats on taxes after his two earlier victories on showdown votes on budget cuts, the leadership reckons, it will have no hope of controlling the House on subsequent votes this year and next.

"It's the Vince Lombardi school of politics, where winning becomes the only thing," said Frank, a freshman liberal who said it was a source of personal anguish to have to oppose Speaker Thomas P. (Tip) O'Neil Jr. (D-Mass.) on the tax issue.

Democrats and Republicans may argue about which party wins the House vote on taxes, but there can be no argument about the real winners of this exercise: the well-to-do in America.

Changes in corporate income tax, personal income tax, estate tax and capital gains tax that now seem certain to win final approval all favor wealthy taxpayers. Low- and middle-income taxpayers get modest reductions in overall tax rates, most of which will be offset by the effects of inflation.

The most important features of the tax bills under consideration affect business investment and basic personal rates. In both cases, whatever bill finally passes is destined to produce sharply reduced revenues for the government compared with today's tax structure.

But the tax bills in the Senate and House also include special-interest provisions for the benefit of specific groups.

For example, the trucking industry has won a concession in the House bill that would permit it to deduct the value of "operating rights" that used to give trucking companies monopoly rights to certain inter-city routes.

With de-regulation of the trucking industry, these operating rights, once bought and sold like New York City taxi medallions, became valueless.

Under the Ways and Means Committee's tax bill, trucking firms would be allowed to deduct from federal tax an amount equal to the price they paid for now-worthless operating rights. Revenue loss from this provision: $120 million in fiscal 1982.

Tax breaks for the prosperous are hardly a new development. The tax code that has appalled self-styled tax reformers for so many years was mostly written by Democratically controlled Congresses, who long ago discovered the benefits of handing out tax advantages to the priviledged.

But in recent years Congress has retained the right to review taxes on approximately a biennial schedule, thus giving members a regular chance to "reduce taxes" (more accurately, to compensate for the effects of inflation-pushed "bracket creep")

This time, under pressure from the White House to enact a three-year tax program, Congress seems destined to enact a bill that will reduce taxes for three years, then index them to inflation.

And that bill will be one closely tied to Republican proposals. In the words of one liberal Democrat who was discussing today's showdown in the House with Reagan and the GOP, "Even if we win, they win."