Unwanted  tags inserted before and after a rendered $item
There can be some better solution of this question but as you are facing of this extra html tag issue inside href, here is solution for this. 

&lt;div class="&lt;?php print $classes; ?&gt;"&lt;?php print $attributes; ?&gt;&gt;
  &lt;?php if (!$label_hidden): ?&gt;
    &lt;div class="field-label"&lt;?php print $title_attributes; ?&gt;&gt;&lt;?php print $label ?&gt;:&amp;nbsp;&lt;/div&gt;
  &lt;?php endif; ?&gt;
  &lt;div class="field-items"&lt;?php print $content_attributes; ?&gt;&gt;
    &lt;?php foreach ($items as $delta =&gt; $item): 
    $phone_link_data = render($item); 
    $phone_link = strip_tags(html_entity_decode($phone_link_data));
    ?&gt;
      &lt;div class="field-item &lt;?php print $delta % 2 ? 'odd' : 'even'; ?&gt;"&lt;?php print $item_attributes[$delta]; ?&gt;&gt;&lt;a href="tel:&lt;?php print $phone_link; ?&gt;"&gt;&lt;?php print render($item); ?&gt;&lt;/a&gt;&lt;/div&gt;
    &lt;?php endforeach; ?&gt;
  &lt;/div&gt;
&lt;/div&gt;