I guess its not a tourist visa. A tourist visa is either 60 days single entry or 180 days multiple entry. To my knowledge there is no 90 days tourist visa.
Its perfectly fine to visit Thailand again on a visa free exempt entry. Many do that 3 or 4 times a year and never have any problems. Its getting more problematic if you try to maximize your stay and have many back to back entries and extensions. You visited 2 times less then 30 days. I would say no worry. Welcome back
This is a old article and for sure it not reflects the current situation. Its no general rule. Only your local immigration can answer it. But i know many demand a new TM30. And comming back from abroad now even requires you to do the first 90 day report in person if your a longstayer