Wet Brining Chicken with aromatics, does it work? Will pressure cooking be more effective?
Greg Blonder has the best information that I've found on the effects of brining and marinating. In fact, the "food myths" section of his website, has a lot of objective food science.  There are several links that are pertinent to your questions. You can see here, that Blonder uses dye to illustrate the effect of brining.  He concludes that brining is almost always a surface treatment (with the exception of shrimp and other arthropods).  Blonder concludes that salt "diffuses faster than any other component in a marinade or rub." Further, he concludes that "most flavor molecules will only penetrate a millimeter or two, thus basically only effecting the surface." 

[On a side note, given that Thanksgiving is almost upon us in the US, Bloder suggests that those folks who enjoy a brined turkey just use salt and water, as the other ingredients added to the brine are fairly useless.]

So, I am afraid that you will not be able to get aromatics to penetrate deep into the chicken (even with injection...he tests that too). 

Since brining and marinating happen before the cook step, I don't think the pressure cooker is relevant to your question.  That may make this question a duplicate of the linked, related question.