Which role is more strategic and has more power in the Tech industry, the PM or the PMM? Who has the final call on products decisions?

Really interesting question. It depends on what you define as power. PMs are responsible for building the product (so they ultimately have the final call on product decisions), but PMMs are tasked with getting that product out in front of the right target user. You can have the best product in the world, but if it isn't marketed, no one will know about it. 

The ideal situation is that PM + PMM work together, tackling big decisions together and that nothing is done in a silo. When you have a rogue PM that makes decisions irregardless of a PMM's customer data, then you have a big problem. 

Mary pretty much nailed this one. Ideally you both have a lot of power and divide it and wield it jointly. But if you need a direct answer to who has the final call on product decisions, it's PM. 

Both must be equally strategic, just in different ways, and often on different timelines. Regarding power, it depends on how you define that. Politically speaking, my instinct says that in most companies it's PM because they "make the stuff." PMM has the "power" to make it succeed or fail in the marketplace, but unless you're a vindictive egomaniac with seriously self-destructive tendencies, chances are you're not going to wield that power to drive an outcome other than success.