Season 2: What is so important about the bridge?

To Xander Feng, the bridge is nothing but a favor to his allies and friends.

In episode 5, the Vice president met him in a trade summit. When they're talking about the projects to be approved, the VP mentioned the Long Island Bridge; Feng stopped the conversation and asked a favor: to continue the lawsuit in the World Trade Organization for currency manipulation. Frank discovered that Xander Feng and Raymond Tusk are trying to manipulate the trade summit. Frank specifically notify that the bridge is very important to the administration but to Feng is only "appearances" to maintain.

What is really important to Feng is to start the Refinery project with Clayton West (Tusk's industry). This hypothesis reinforces when in Episode 7; some strange donations is starting to appear and is used in bad propaganda for democrats in face to midterms elections. Underwood discover the Feng-Tusk scheme and send Douglas Stamper to negotiate with Feng one more time; Feng asked to start ASAP the Long Island project. Remember, Feng is the one who rejected the bridge project in episode 5 after the chaos in the summit and Douglas asked why this strange change of mind but the reason was the simplest:

Xander Feng: I have allies who want the bridge. Without it, they become my enemies.

So again, the bridge is nothing to Xander, the refinery is the big fish.