I haven't had Wyll's scene trigger for me since patch 6 and I assume that it is now tied to flirting with him at the beach during the Tiefling party (like you mentioned). Previously it would always play unless you had been flirting with two other companions. So this might be the reason why it doesn't play for you now. But yes it usually plays during one of the early LR in the Shadow Curse (the first always is another Guardian Dream, I iirc) so you not LRing enough probably is not the issue.
In general you have to start flirting with your chosen companion/s in act 1 for the romance to progress in act 2. Though I have heard someone say, that you can start some in Act 2, but I wouldn't know about that from my games.
