Since an active day is one where you have 500 steps, you will qualify just for walking from the parking lot into the bowling alley and back again. But just because you get the exercise credit without doing anything more, you should go ahead and bowl a few games while you're there.
The only thing that counts was a "activity" is either checking into a Silver Sneakers gym (but you don't have to do any exercise) or walking "at least" 500 step in a day (and unless one is confined to bed it is impossible not to get).To get a reward you need to do these "activities" on 8 different days for that month.
Your bowling would be more than 500 steps. If you don't have a fitness tracker you can claim then using this form and mailing them in.
Go365 Medicare Workout Tracker 2019.pdf