Here is a dharma talk by Zen priest Gil Fronsdal about the Four Great Vows and their connections to the 4 Noble Truths.
http://www.chzc.org/Fronsdal.htm" onclick="window.open(this.href);return false;" onclick="window.open(this.href);return false;
"On initial contact with these great wonderful vows that lie at the heart of Zen Buddhism..."
This quote from the talk confirmed my feeling the Four Vows are a core part of Zen practice. They represent the Bodhisattva ideal in condensed form. No method in Zen, whether strange or ordinary is undertaken for one's own benefit alone, but is done in order to try to benefit all beings.