Hi Ian,
I’ve not previously seen the ability to target product tags assigned to line items within Flow, but I can suggest a solution for you to consider.
Our Order Tagger app allows you to create rules that will tag your orders based on a set of criteria and conditions. We have a criteria that will analyse the product tags of all products contained within an order and check them against the conditions that you specify, e.g. is the tag “Vegan” contained within the product tags.
You can then apply a fixed tag to the order if your conditions are met, or, you can use our dynamic tagging feature to apply ALL of the product tags as order tags.
Then, using our Order Tagger Flow Trigger, you can create a workflow which will be triggered 30 seconds after Order Tagger has finished tagging or untagging an order.
Your workflow can be set to look for a specific Order Tag and, if found, you can use Flow’s built-in actions to send an email to your admin team.
We have an article that covers the flow set-up of this scenario here which may help: Using Order Tagger as a Trigger in Shopify Flow
There are probably other decent solutions available so it’s worth having a good look around. I’d be happy to answer any questions you have about Order Tagger if you’re keen to find out more.