This seems like a bug in the Google Play Services library similar to the one I reported some time ago.
I just tried
map.addPolyline(new PolylineOptions()
.add(new LatLng(90, 5))
.add(new LatLng(-90, 5))
.width(2)
.color(Color.BLUE));
and it draws a line from 0,0
to 0,5
on low zoom levels and from 0,5
to 90,5
after you zoom in. Both are of course incorrect.
A workaround would be to use 85
instead
map.addPolyline(new PolylineOptions()
.add(new LatLng(85, 5))
.add(new LatLng(-85, 5))
.width(2)
.color(Color.BLUE));
but don't ask me why it works correctly this way...
You may also want to add more info to the linked issue report.