Some folks syncretically wed him with Eros the Elder, and some Orphic sects saw him as the “ancestral force” (if you will) behind (Zagreus/) Dionysos. At least, if I understand what they're saying, anyway.
As noted in the Theoi article: “His name means bring to light or make appear from the Greek verbs phanaô and phainô.” One would compare this to the idea of Dionysos as “the God who comes,” or “the Lord of Epiphany.”
Orphic Hymn #5 is dedicated to him, as the Protogonus. Like Dionysos, he also seems to have a tendency to hang out with cosmic snakes.
Sometimes, when I use the title “Lucifer” (Light Bringer) I'm being an asshole and referring to Phanes, Iakkhos, or Prometheus. (Although I tend to refer to Prometheus as such.) My reasons for Iakkhos are entirely UPG (I experienced him as “joyous torchlight at midnight,” but hardly expect that to makes any sense to most folks).
I primarily do this to freak out people I don't want to deal with. It's done a pretty good job of keeping me from being overly annoyed in terms of those who I speak with, honestly. They mistake me for a Satanist, and I get to roflcopter along most of the time.
I lampoon the idea of the Black Brotherhood, on an unrelated note, for reasons of satire.