I haven't gotten any ghosts yet, but my wife got 2 in the 13 games we played yesterday (all losses! Woo!). She's using Vision of Confluence and Ice Breaker since she's not much of a PvP'er so I told her just use her favorites. Anyway, she's I think 276 light with those equipped, and her ghosts were both around 285, so my guess is that yes, it does influence the level of the ghosts when (if) they drop.