Spinning 10 unique PokéStops within 30 minutes results in a 'Mega PokéStop', where you receive 6+ items and 100 XP. But what if some of the PokéStops result in a 'Bag Full' message, do those stops count towards the bonus?
I noticed that you said that spinning 10 unique Pokestops in 30 minutes results in the bonus. I believe the mechanics are slightly different. From here:
It's not actually 10 unique in 30 minutes, as is widely believed. It's 10 unique with no more than 10 minutes between spins of unique Pokestops. It usually takes me 40 or so to get my 10th spin on my way to work. Bonus still triggers.
Yes, stops spun while your bag is full will still count towards the 10th Pokestop bonus. See here:
On my ride in to work I can hit anywhere from 30-40 unique stops. Obviously this fills my bag up pretty quick. Today, i got a 10th hit bag bonus, and then the next stop I hit my inventory limit with 9 more stops left in my route. I didn't feel like cleaning anything out, but i always continue to spin the stops i pass for that sweet sweet 50 XP (#AllXPMatters) As I got closer to work, I caught a caterpie and a magikarp, allowing me to get items from stops #9 and 10. When I did, i received 7 items from the 10th stop, even though my journal only has record of me hitting 3, since stops that give you the "bag full" message aren't counted
tl;dr: If you spin stops with a full bag, if you clear space before the 10th unique spin, you still get the bonus items
In addition, you still get the exp bonus from the 10th stop even if your bag is full