
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.