YES Pea shoots are just the more edible tender portions of the vine. They're fine to be mixed in your rotation of tortoise food from time to time. Here's what the Tortoise Table says about Bean plants which are in the same family...http://www.thetortoisetable.org.uk/site/plants_19.asp?catID=494
I grow sugar snap pea seeds and squash seeds inside as a winter tortoise treat... Good stuff!