The House Banking Committee yesterday sent to the floor a $23.6 billion housing authorization bill that far exceeds President Reagan's recommendations, particularly in subsidized housing for the poor.

The bill would reverse some budget cuts Congress voted at Reagan's behest in his first two years in office. It would move low-income tenants' share of the rent in assisted housing back to 25 percent of their income from the 30 percent to which Congress lifted it in 1981. It also would expand subsidized housing stock by 135,000 units, and support them more generously than Reagan wants.

And it would drop entirely the administration's plan to start delivering rent subsidies in the form of vouchers, which tenants could use to shop for suitable housing.

This proposal, which committee Republicans called "the key element in the administration's assisted housing legislation," was never even brought up. During debate in the housing subcommittee two weeks ago, Rep. Stewart B. McKinney (R-Conn.) proposed a scaled-down experimental program, but his amendment was rejected on a voice vote.

The bill approved yesterday would reauthorize the Community Development Block Grant and Urban Development Action Grant programs for three years. It would also create a new, $15 million program of neighborhood development grants designed to help aid small businesses and generate jobs in distressed neighborhoods. Major authorization levels in the bill:

* Provide $13.094 billion for low-income assisted housing.

* Provide $1.55 billion for public housing operating subsidies.

Provide $3.955 billion for rural housing.

* Provide $4.5 billion for the CDBG program.

* Provide $440 million for the UDAG program.

The total is substantially higher than the $17.6 billion approved by the Senate Banking Committee last month; the bulk of the disparity comes in low-income assisted housing. The Senate bill would authorize only $7.6 billion for those programs.

If both bills emerge from the floor in their current forms, it will make for "a very difficult conference," according to one House housing subcommittee staff member. But staffs from both the House and Senate panels say they think the chances are good that Congress will manage to pass a housing bill--something it was unable to do last year.

In addition to lowering the tenants' share of the rent in assisted housing, the House bill also would block some administrative changes the Department of Housing and Urban Development is planning.

One such change, scheduled to become final next month, would alter the formula for calculating the fair market rents for housing subsidized under part of the Section 8 program. Currently, fair market rents-- the key to how much HUD will pay in subsidy in a given area--are based on, among other things, the 50th percentile of rents in a market area. HUD has proposed a rule that would change this to the 40th percentile. The House bill would peg the standard to the median again.

Finally, the bill would tighten up both application and targeting requirements for Community Development Block Grants, directing that at least 51 percent of the grant money go to benefit low- and moderate-income people.

And it would change the application process so that communities would have to spell out their methods and goals in using a grant, thus making it easier for both the government and people in the local community to keep track of how the money is being used.