there is a clause that allows you to use your regular attack bonus instead of the one of your polymorph spell
so if you got a really good attack (or use underleveleld polymorphs) you still get something out of your handwraps
and considering that your handwraps are good for your wild morph damage they still might be a good choice
Also please note that striking rune says
"increasing the weapon damage dice it deals to two instead of one"
It does NOT double the number of dice. It explicitly raises from one to two. Given that, you get to a situation where for example, the agile attack of the Cat form would double its attack dice from 1d10 to 2d10 but the regular attack wouldn't increase its 2d6. Makes no sense.
Seems clear that the form spells' damage numbers are already scaled by design and do not interact with a striking rune.