In Mass Effect 3:
Video is subtitled with open captions, but here's a transcript for people with crappy internet:
IMMIGRATION OFFICER: So you admit you and your thugs are here illegally?
ARIA: Yes. And it only took C-Sec three weeks to figure it out.
IMMIGRATION OFFICER: I don't care who you are -- you're required to go through processing like all other refugees. Come with me.
ARIA: I don't think so. Sheerk, get me the asari councilor. [Lowercase asari in original subtitles.]
Beat. A hologram of COUNCILOR IRISSA appears.
IRISSA: Aria, to what do I owe the pleasure?
ARIA: I'm being asked to submit to immigration processing.
IRISSA: I see.
IRISSA reaches out of frame and appears to manipulate some unseen controls.
IRISSA: And now you've been processed. Is there anything else?
ARIA: Nothing, thank you.
The dialogue is mildly different if Tevos is the Asari Councilor instead of Irissa, but there is no substantial change in outcome. This suggests to me that Aria's hold over the Councilor is political rather than personal. However, the scene doesn't really elaborate on this.
We might suppose that the Councilor felt threatened by Aria's position as a gang leader, except that Aria is not a gang leader at this point. All three major Omega gangs have abandoned her (and she very conveniently needs Shepard's help to get them back on her side). Also, while Tevos might be intimidated, it seems less plausible that Irissa would put up with that kind of pressure.
What is the basis of Aria's control over the Asari Councilor?