As always the answer pops up just after asking the question...
My model doesn't have the usual ID set up (it has key in field "ID") so I had to add that to the schema and the meta data otherwise I guess all the models were thought to have the same empty key and so wouldn't iterate.
Updated Model code:
namespace app\models;
class POI extends \lithium\data\Model {
protected $_meta = array(
'source' => 'POI',
'key' => 'ID'
);
public $_schema = array(
'ID' => array('type'=>'id'),
'Name' => array('type'=>'string','null'=>false)
);
}
Hope this can help someone else in the future!