Drupal commerce get quantity per sku in hook_commerce_checkout_complete
You need to wrap the $order object before looping over the line items. It also removes the need to wrap the line items explicitly.

$order_wrapper = entity_metadata_wrapper('commerce_order', $order);
foreach ( $order_wrapper-&gt;commerce_line_items as $line_item_wrapper ) {
  if ($line_item_wrapper-&gt;commerce_product-&gt;sku-&gt;value() == 'some-SKU') {
    // increment quantity counter, award points etc.
  }
}