parents siblings selector

HTML

<div id="radbtnContainer" style="float: left"> 
    <span class="radBtnShoppingBag">
        <input id="ctl00_ctl00__nestedContent__mainpageContent_BasketViewProducts_radbtnContinue" type="radio" name="ctl00$ctl00$_nestedContent$_mainpageContent$BasketViewProducts$radButton" value="radbtnContinue" checked="checked">
    </span>
    <label for="ctl00_ctl00__nestedContent__mainpageContent_BasketViewProducts_radbtnContinue" class="labelRadioGroup">aaaa</label> 
    <br>
    <span class="radBtnShoppingBag">
        <input id="ctl00_ctl00__nestedContent__mainpageContent_BasketViewProducts_radbtnCollect" type="radio" name="ctl00$ctl00$_nestedContent$_mainpageContent$BasketViewProducts$radButton" value="radbtnCollect">
    </span>
    <label for="ctl00_ctl00__nestedContent__mainpageContent_BasketViewProducts_radbtnCollect" class="labelRadioGroup">bbbb</label>
</div>

CSS

#radbtnContainer label {
    display: block;
    float: left;
    color: #000;
    cursor: pointer;
    height: 30px;
}
#radbtnContainer .radBtnShoppingBag + label {
    color:red;
    height:30px;  
}
#radbtnContainer label.is-checked {
    color:blue;
}

JavaScript

$('input[type=radio]:checked')
    .parent('span.radBtnShoppingBag')
    .next('label.labelRadioGroup')
    .addClass('is-checked');

$('input[type=radio]').change(function () {
    $('label.labelRadioGroup').removeClass('is-checked');
    $('input[type=radio]:checked')
        .parent('span.radBtnShoppingBag')
        .next('label.labelRadioGroup')
        .addClass('is-checked');


});