tlp-stat and power indicator show different battery levels

I'd say both are:

since it says Capacity 90% and Charge 95,9% I would guess the menu bar shows you

Charge * Capacity = RealCharge
95,9%. * 90%      = 86,3%

Capacity is the maximum capacity that your battery is able to charge to. This can and will decrease with time for technical reasons, and your battery will charge and discharge faster as it gets older because of this decreased capacity. This value might differ slightly while charging but should more or less only decrease with time.

Charge is the percentage of how charged your battery is compared with its maximum capacity.