Pretty sure it will count towards your max spend for the month. You could always phone them to confirm.
Edit:
Phoned them on your behalf and they confirmed it. If you buy a pair of shoes for the shoe booster benefit, that purchase will count towards your max spend for healthygear for the month.
You could always buy the clothes the following month to make sure you don't lose out on the healthygear benefit.
Also check which items qualify for healthygear, as not all item purchases qualify for the benefit.
Thanks for finding out for me. I usually prefer asking forums because I find that the end users know more than the contact staff. I guess ill have to weigh up what i need more urgently: clothes or shoes.