I know this is an "older" post. This question and the provided answers helped me get ideas for my own problem. I think this solution addresses the OP question (intersecting borders with 4 and 2 columns depending on display)
Fiddle: https://jsfiddle.net/tqmfpwhv/1/
css based on OP information, media query at end is for med & lg view.
.vr-all {
padding:0px;
border-right:1px solid #CC0000;
}
.vr-xs {
padding:0px;
}
.vr-md {
padding:0px;
}
.hrspacing { padding:0px; }
.hrcolor {
border-color: #CC0000;
border-style: solid;
border-bottom: 1px;
margin:0px;
padding:0px;
}
/* for medium and up */
@media(min-width:992px){
.vr-xs {
border-right:1px solid #CC0000;
}
}
html adjustments to OP provided code. Red border and Img links for example.
<div class="container">
<div class="row">
<div class="col-xs-6 col-sm-6 col-md-3 text-center vr-all" id="one">
<h5>Rich Media Ad Production</h5>
<img src="http://png-1.findicons.com/files/icons/2338/reflection/128/mobile_phone.png" />
</div>
<div class="col-xs-6 col-sm-6 col-md-3 text-center vr-xs" id="two">
<h5>Web Design & Development</h5>
<img src="http://png-1.findicons.com/files/icons/2338/reflection/128/mobile_phone.png" >
</div>
<!-- hr for only x-small/small viewports -->
<div class="col-xs-12 col-sm-12 hidden-md hidden-lg hrspacing"><hr class="hrcolor"></div>
<div class="col-xs-6 col-sm-6 col-md-3 text-center vr-all" id="three">
<h5>Mobile Apps Development</h5>
<img src="http://png-1.findicons.com/files/icons/2338/reflection/128/mobile_phone.png" >
</div>
<div class="col-xs-6 col-sm-6 col-md-3 text-center vr-md" id="four">
<h5>Creative Design</h5>
<img src="http://png-1.findicons.com/files/icons/2338/reflection/128/mobile_phone.png" >
</div>
<!-- hr for for all viewports -->
<div class="col-xs-12 hrspacing"><hr class="hrcolor"></div>
<div class="col-xs-6 col-sm-6 col-md-3 text-center vr-all" id="five">
<h5>Web Analytics</h5>
<img src="http://png-1.findicons.com/files/icons/2338/reflection/128/mobile_phone.png" >
</div>
<div class="col-xs-6 col-sm-6 col-md-3 text-center vr-xs" id="six">
<h5>Search Engine Marketing</h5>
<img src="http://png-1.findicons.com/files/icons/2338/reflection/128/mobile_phone.png" >
</div>
<!-- hr for only x-small/small viewports -->
<div class="col-xs-12 col-sm-12 hidden-md hidden-lg hrspacing"><hr class="hrcolor"></div>
<div class="col-xs-6 col-sm-6 col-md-3 text-center vr-all" id="seven">
<h5>Mobile Apps Development</h5>
<img src="http://png-1.findicons.com/files/icons/2338/reflection/128/mobile_phone.png" >
</div>
<div class="col-xs-6 col-sm-6 col-md-3 text-center vr-md" id="eight">
<h5>Quality Assurance</h5>
<img src="http://png-1.findicons.com/files/icons/2338/reflection/128/mobile_phone.png" >
</div>
</div>
</div>