Ironically, Acer on their support FAQ recommends checking for a label on the bottom that says "Bluetooth". So, just buy it, check the bottom, and eat the restocking fee if it does not have that label. The button is a facade. It's on my 5610Z, but there is nothing behind it. Some without can be upgraded and some cannot. If you own it, try calling Acer for parts. It'll be expensive, but that would be your best shot. Also, Ebay has some none OEM blue tooth modules for fairly cheap for Acer laptops. The model numbers are listed with each version based on the cable design.
I am really tired of this new coorporate mindset of make so many different models that even the manufacturer or seller have no clue what they make or features that each unit has.