I realize I'm late in replying, but in case anyone else has this question....
NO definitely not tracking you. That is not indicative of someone trying to spy on you. That file contains only the location of something on a map (like a restaurant, bar, friends house, etc.). I actually was curious about the same thing. It's a very fancy way of iPhone users "texting" map directions to each other.
For example, let's say we were to meet at a friends house. I could say, "Hey Sarah, meet me at Jimmy's apartment. The address is 1234 Sycammore St. San Simeon, CA 98732." From there you would have to manually open the Map App on your phone, type in the long address, and wait for directions.
The OTHER option is to text you the map itself so that when you click on it, everything is done for you. That is what you are seeing. So when you get the text (that ".loc.vcf" file) all you have to do is tap on that map picture/text message and your phone will automatically open the Maps App for you and already input the address you want to go to. It's kind of a convenience thing. I guess it also give you a little preview in your text message since it usually is a map image that gets shown along with the file.
So let's take a look at his perspective and how this happened:
On his iPhone he would open Apple Maps. Find the location of his friend's house, for instance. And then he would hit the "share" button in the Maps App. He would select the "send to iPhone/text message" option. So basically he's sending you a file that has 1) the location of the address and 2) directions for your phone to automatically open the map app and give you directions without you having to manually do it.
I hope that made sense!!!
*If you don't have an iPhone then all you will see is that ".loc.vcf" file and it won't do anything on your phone.