MAGETWO-31324: Tax labels aren't displayed for Bundle options of "multiple select" & "drop-down" types

- QA plus format fix

Author: Cristian Partica

app/code/Magento/Tax/Model/Observer.php

@@ -312,7 +312,7 @@ public function updateProductOptions(\Magento\Framework\Event\Observer $observer
             $options['optionTemplate'] = sprintf(
                 '<%%= data.label %%>'
                 . '<%% if (data.finalPrice.value) { %%>'
-                . ' <%%= data.finalPrice.formatted %%> (%1$s <%%= data.basePrice.formatted %%>)'
+                . ' +<%%= data.finalPrice.formatted %%> (%1$s <%%= data.basePrice.formatted %%>)'
                 . '<%% } %%>',
                 __('Excl. tax:')
             );