Guild Wars 2

When getting additional damage in(%) from some of the runes and sigils, are they applied to phantasms as well? or to illusions in general ?

As of right now, none of them apply to our phantasms.

As far as I know, the only equipment and / or buffs placed on the Mesmer that can also be applied to Phantasms are ones that directly effect your base primary stats.

Examples of things that will increase Phantasm stats:

Stacks from Superior Sigil of Bloodlust (Directly increases Power)
Stacks of Might (Directly increases Power)
Stacks from Superior Sigil of Perception (Directly increases Precision)
Power, Precision, and Toughness from Equipment or Traits.

Examples of things that will not increase Phantasm stats:

Fury (on Mesmer, not from Phantasmal Fury)
Superior Sigil of Force (or Accuracy)
Vitality from Equipment or Traits

Other traits that specify that they improve Illusions or Phantasms are exceptions, of course.