Two quests give Rowena's Tokens:

To Tussle with Gods
The prerequisite is "Ifrit Ain't Broke", which means that you have to defeat all of the EX primals to unlock this (since Ifrit is last). It is given by Urianger at the Waking Sands. This gives 3 Rowena's Tokens.

Primal Focus
The prerequisite is "To Tussle with Gods" (above), and is given by Laraina in Mor Dhona. This gives 3 Rowena's Tokens.