The environmental proposals that the Clinton Administration is sending to Congress in its budget request for the year 2000 include new ways for delivering money to state and local governments to spend as they see fit, a sign that environmental power-sharing is taking a firmer hold than ever before. The Adminstration is seeking to spend $34 billion on environmental programs in the fiscal year that begins on Oct. 1, a 5 percent increase over the amount Congress approved for the current fiscal year.