Sorry for the delayed response to this. I've been looking at your page, and I honestly am not sure what's wrong. There is a Javascript error on the page, which may be preventing the G+ button (which is very heavily Javascript dependent) from loading. The error is coming from LinkedIn from one of your Apply buttons. The error is:
Uncaught Error: no JobTitle provided framework?v=0.0.2000-RC1.29365-1407&lang=undefined:1329
The problem apply button looks to be from this code:
<script type="IN/Apply" data-companyid="2428569" data-email="<email>" data-joblocation="Singapore" data-logo="<domain>/templates/siteground6/images/header.jpg" data-themecolor="#5573b7" data-phone="required"></script>
Hopefully, that helps you find the specific apply button that you need to update with the Job Title.
I honestly don't think that that Javascript error is preventing the G+ button from loading, but I really don't have any better suggestions as to what to look into now. Please fix that and see if it helps. The next thing to test would be if it works with an alternate template, like the standard Joomla rhuk_milkyway template.
I hope that helps get you going,
Alex