By Diane Bartz WASHINGTON (Reuters) – Dozens of companies and business organizations sent a letter to U.S. Congress members on Monday, urging them to support a bill that would rein in the biggest tech companies such as Amazon.com and Alphabet’s Google. Last week, Democratic U.S. Senator Amy Klobuchar and lawmakers from both parties said they had the Senate votes needed to pass legislation that would prevent tech platforms, including Apple and Facebook, from favoring their own businesses. Companies supporting the measure, which include Yelp, Sonos, DuckDuckGo and Spotify, called it a “moderate …