Question: Do the yellow bars on the top/bottom/left/right of map points of interest signify anything? I've noticed 0, 1 and 2 bars.
As seen in the highlighted encounter (blue triangle) shown in the screenshot below, as well as the Phone Recording to the right.

[![enter image description here](https://i.stack.imgur.com/snKYr.jpg)](https://i.stack.imgur.com/snKYr.jpg)

Answer: 
It appears to be markers to that show up opposite the POI from the center of your screen (at least on the PC version.) 

I took a short video of it, here, that you can see. Watch as I move the map around, the dots move around, so that they are always on the opposite side of the POI from the center of my screen. They don't appear to serve any purpose other than decorative.
Tldr :Those are markers to help you navigate. Use the corresponding arrow keys (bar on right = right arrow, etc.) to select that icon.
Info :
You will probably encounter icons that you can't reach using the mouse from time to time. It can be frustrating if you want to fast travel to them. Fortunately, using the arrows keys, you can select and navigate through those icons. Those markers indicate which icon you will select using the corresponding arrow key.