I've noticed that the tooltips for certain Elite's don't adjust their DPS in some cases when under a buff, which brings into question if these buffs are working properly on them.
For example, Wazmakka's ranged damage is buffed by the Waaagh buff but not his melee damage. Likewise, Macha's ranged damage goes up when she uses her Psyker Blast but not her melee damage.
I'm not sure where else this is the case. I would suspect that for most elites with both melee and ranged, it only affects their primary weapon (i.e warp spider attack buff after teleport only affecting ranged) but I haven't tested.
Thought I would just bring it to Relic's attention and they can confirm better than me if the behaviour is intended.