All you have to do is override the renderer function which returns a span element with bootstrap's label css class.
{
header: 'Status',
dataIndex: 'status',
width: 100,
renderer: function(value, meta, record) {
var cls;
if (value === 'Success') {
cls = 'label label-success';
} else if (value === 'Failure') {
cls = 'label label-important';
} else if (value === 'Processing') {
cls = 'label label-warning';
}
return Ext.String.format('<span class="{0}">{1}</span>', cls, value);
}
}
The code above is tested with Ext JS 5.0.1.