JSFiddle - React, Tailwind, and code Playground
HTML
<link rel="stylesheet" href="http://twitter.github.com/bootstrap/assets/css/bootstrap.css">
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8" />
<title>Test #1</title>
<meta name="viewport" content="width=device-width, initial-scale=1.0">
</head>
<body>
<div class="container-fluid">
<div class="row-fluid">
<form class="well">
<legend>Not working</legend>
<p>As you can see, the "Bar" label is not aligned with the input element below it.</p>
<div class="controls controls-row">
<label class="span9"><span>Foo</span></label>
<label class="span2"><span>Bar</span></label>
</div>
<div class="controls controls-row">
<input type="text" class="span9" />
<input type="text" class="span2" />
</div>
</form>
</div>
<div class="row-fluid">
<form class="well">
<legend>Workaround</legend>
<p>It works when wrapping the form elements, but that creates a lot of superfluous DIVs.</p>
<div class="controls controls-row">
<div class="span9">
<label><span>Foo</span></label>
</div>
<div class="span2">
<label><span>Bar</span></label>
</div>
</div>
<div class="controls controls-row">
<div class="span9">
<input type="text" class="span12" />
</div>
<div class="span2">
<input type="text" class="span12" />
</div>
</div>
</form>
</div>
</div>
</body>
</html>