JSFiddle - React, Tailwind, and code Playground

HTML

<div id="welcome">
    <div class="search-row">
      <div class="postcode-search col-lg-4">
        <div id="postcode-search" class="input-group">
          <input type="text" id="postcode-bar" class="form-control" placeholder="Enter postcode.."/>
          <span class="input-group-btn">
            <button class="btn btn-default" id="postcode-btn" type="button">FIND STORES</button>
          </span>
        </div>
      </div>
    </div>
  </div>

CSS

#welcome {
    height: 220px;
    border: 1px solid yellow;
    
}
#postcode-search {
    margin: 0 auto;
    padding: 0px;
    text-align:center;
}
#postcode-bar {
    height: 50px;
    background-color: #fff;
    text-align: center;
    font-size: 13px;
    
}
#postcode-btn {
    height: 50px;
}