What app are you using for battery health cycles and health %? I've found coconutBattery to be the most accurate. The health % can vary 5% depending on % of charge - so I only measure it once it's charged 100%.
I've had my iPhone 6s+ for almost 3 months and I have 21 cycles. I'm probably a medium to light user as I do most of my reading/gaming on my iPad. Battery health is above 100%. I had some 250+ cycles? on my iPhone 6+ that I had for almost 1.5 years.
Battery health: Try not to drain below 20% if you can help it. Don't put it in the sun (keep it out of heat).