You can double check the scenes you've completed in the menu by going to Quest Log > Achievements. You can click on the Build #s and each event is sorted by the place they're available at.
Off the top of my head, three events that give a decent-sized relationship boost are:
• The first time you drink with Rohan at Finn's tavern ("Look around" after 10PM)
• The group event at the tavern ("Look around" on Friday nights after 11PM). Choose to sit beside him.
• The bonfire event. Once you near the end of the "Outside The Law" questline, you can talk to Rohan about "Stress Relief". This starts a side-quest, with an event available at the field. Choose to sit beside him.
(Just a tip: each group event allows only one relationship boost, even if they're repeatable, and it goes to the first one you choose/sit with.)
Also, as I said before, 0.6 brings the end to the "Outside The Law" quest, which provides a huge boost of friendship to everyone. I'm also tweaking some things in 0.7 to make his CG a bit easier to access. :)
