Do you need to submit separate XML sitemap for amp pages?
No, you don’t need to create a separate XML sitemap for amp pages, confirmed by John Mueller from Google.
According to him,
rel= amphtml is sufficient to tell Google about the AMP version of the page.
Here is the tweet.
— John Mueller (@JohnMu) October 13, 2016
So if you have already implemented AMP to your site, Google will automatically pick the AMP pages. Which means, you don’t have to create and submit separate XML sitemap for amp pages.
Also read : Google introduces new AMP pages testing tools