Depends. If we consider 15k limit and 10x (by 10x I don't mean 1x+9x as pharmeasy/hotel gives, I mean 1x+4x+5x[next month]), then the spend can be 112500. You won't max out base + bonus and also get 5x next month (as t&c says 90 days).
If that 5x extra comes in same month, then 49000~, as you'll cap this to 15k.
Also hdfc and some users say the capping of extra 5x will be of the trxn month, some say it is for the month when it is credited, some even say extra 5x is exclusive of any month capping. No one answers this in absolute sense.