If you like your current frame tt keep it.
I'm 5'8" (done growing lol) and recently went from 8.5 bar back to 8.25. Got a 22mm top stem and 7mm spacer down from 24mm top on 10mm spacer. that's on a 20.5 tt frame.. I like the lower setup a lot more...got my high hops back but im not as hunched over as I was on my old front load stem. Everything's preference though, depends how you like to ride.
This is how i see it:
Bar/stem height has to do with torso length.
TT length has to do with how tall you are entirely.
at 5'6, if I were you, I would get something 20.5 tt and keep your current bars since the Chula stem is huge.
FREE not under the control or in the power of another; able to act or be done as one wishes
STYLE a particular, distinctive, or characteristic mode of action or manner of acting