Q: I don't see a favorites option in Apple maps on my iPhone 6

If you bring up maps on the phone and tap on the search field on the top of the screen, you should see a list the last places you have looked for, Favorites should be the first item on that list.

copied from iPhone User Guide 9 /Maps/Find places

IF you have ios10, the favorites is no more. The screen has been "monetized" by Tripadvisor, leaving less room for other functions.