From the FAQs:
Is there a maximum number of base award miles that can be earned on a ticket?
Yes, a maximum of 75,000 miles will be awarded per ticket (inclusive of any class of service and elite status bonus miles).
To my mind a "ticket" is based on the old paper tickets, and consists of four coupons.
When I purchase a Oneworld Explorer ticket, it usually has 16 flights and so consists of four tickets
So would the limit of 75,000 award miles be for each ticket, or for all four tickets - in other words the limit would apply to my entire RTW journey?