How to Place Text Over a Parallax Scrolling Image

You have to adjust the structure of your HTML content so you #header is before your .parallax. Using your desired style:

.parallax{
    background-image: url("https://images.pexels.com/photos/349608/pexels-photo-349608.jpeg?w=1260&h=750&auto=compress&cs=tinysrgb");
    min-height: 500px; 
    background-attachment: fixed;
    background-position: center;
    background-repeat: no-repeat;
    background-size: cover;
    margin: 0;
}

#header{
  position: absolute;
  z-index: 1000;
  top: 200px;
  left: 200px;
}

.text-box{
	height: 600px;
	padding: 50px;
}
@media only screen and (max-device-width: 1024px) {
    .parallax {
        background-attachment: scroll;
    }
}

.navbar {
    margin-bottom: 0 !important;
}
<title>Bootstrap Default Template</title>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
<body>
<h1 id="header">Text</h1>
<div class="parallax"></div>
<div class="col-lg-12 text-box text-center">
<h1>Restauraunt Heading</h1>
</div>
</body>


Another solution is to simply put your h1 into a paralax div...

.parallax{
    background-image: url("https://images.pexels.com/photos/349608/pexels-photo-349608.jpeg?w=1260&h=750&auto=compress&cs=tinysrgb");
    min-height: 500px; 
    background-attachment: fixed;
    background-position: center;
    background-repeat: no-repeat;
    background-size: cover;
    margin: 0;
    position:relative;

}
.text-box{
	height: 600px;
	padding: 50px;
}
@media only screen and (max-device-width: 1024px) {
    .parallax {
        background-attachment: scroll;
    }
}
#header{
 position: absolute;
  top: 50%;
  -webkit-transform: translateY(-50%);
  -ms-transform: translateY(-50%);
  transform: translateY(-50%);
}
.navbar {
    margin-bottom: 0 !important;
}
<title>Bootstrap Default Template</title>
<link rel="stylesheet" href="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/css/bootstrap.min.css">
<script src="https://ajax.googleapis.com/ajax/libs/jquery/3.1.1/jquery.min.js"></script>
<script src="https://maxcdn.bootstrapcdn.com/bootstrap/3.3.7/js/bootstrap.min.js"></script>
<body>
<div class="parallax"><h1 id="header">Text</h1></div>
<div class="col-lg-12 text-box text-center">
<h1>Restauraunt Heading</h1>

</div>
</body>