Erenville talks about the whalaqee. Depending on your version, the context is either presented as a fact (in english) or just as rumors (in japanese). In english he states the whalaqee revere the blue flames made by ceruleum. In japanese its rumored the whalaqee view the ceruleum (aka blue phosphorous water) as sacred. Erenville has no comments about you being a blue mage or your prior experiences with the whalaqee.
For the fisher questline you meet a fledgling blue mage who only knows Flying Sardine. If you done blue mage content, you will have extra dialogue options about how you also did that kind of content. The book from 6.55 also has a dialogue option.
In a Shaaloani sidequest chain, you come across oozes made of ceruleum. A different tribe views the ceruleum as destructive as it can create some sort of creature, referred to as a blue devil, that caused widespread fires in the old days. There is no dialogue that references you as blue mage or that you know of the whalaqee.