Welcome to Android Central! Signal bar indicators can't always be directly compared between different devices, because the software they use to convert the signal strength into bars might differ. Go to Settings>About Phone, and look at the signal strength--what does it say? Do you actually notice any problems with reception when you're using the phone (either on a call or on mobile data)?
Do you have a case on the S6? Some cases might impact signal reception, especially if they're metal.
04-20-2015 01:19 PM