In short: no.  Redirecting all mobile traffic to AMP isn't something that Shopify supports.

Shopify allows "301 redirects" but Shopify has no support for "Mobile-only 301 redirects".  Shopify controls the server-side of your shop, so any server-side redirection would happen from Shopify.  Right now they only have a way of redirecting "all" traffic, and they don't have a concept of "mobile-only" redirects.  If you're itching for this feature, as AMP becomes more and more popular on the mobile web, we highly recommend contacting Shopify and suggesting it!

What about Ads?

Yes, you can send all mobile traffic to AMP pages.  We've created an awesome tutorial for Google Shopping, and Google has created their own awesome tutorial for AdWords

• Google Shopping: How to Send all Google Shopping mobile traffic to AMP pages.
• Google AdWords: How to send all Google Ads (formerly AdWords) mobile traffic to AMP pages.

But I really want all mobile traffic to go to AMP

In rare instances we have seen users perform mobile-redirects one of two ways: Before shopify receives the traffic (at the DNS layer), or after shopify renders the page (on the front-end using JavaScript).  We do not recommend either of these approaches as they can be highly problematic, and therefore we cannot suggest you do these, but it may be worth asking your webmaster if they want to experiment with either process.