I found a similarity between Ishikk's Religion (Roshar) and the Trelagism (Scadrial).
Both of them worship a God who has a jealous brother!! (Ok it's a bit weak... and I only have some quotes wrapped in a bunch of disconnected ideas... but maybe it can help...).
— The Well of Ascension Chapter 9 - Sazed tries to offer the religion to Vin
— The Way of Kings Interlude I-1 - Ishikk discussing his religion with the worldhoppers
From what I could find referring to Ishikk's religion (which, I belive, was only mentioned on his interlude in TWoK) this is as far as the similarity goes.
One major problem to this being the same religion is the reference (or rather, lack of it) to the moons. Scadrial has no moons (as already confirmed by Brandon Sanderson). The Trelagism is based on the believes of Trell's thousands eyes (the stars) and Trell's brother only eye (the sun), there is no mention of a larger "eye" for Trell that would indicate a moon in it's believes. Roshar, on the other hand, has 3 moons, and I could not find references to the stars having any major impact in Roshar cultures.
I found one other quote that might be of interest thought:
— The Way of Kings Chapter 46 - Kaladin's storm dream (the face is supposedly of Tanavast, the Almighty?).
Also, on a side note, I found this reference "It was the time between moons, and so he was lit mostly by the firelight; there was a spray of stars in the sky above." (TWoK) the "spray of stars" might refer to the same stars as seen from Scadrial ie:"There is a very bright star patch, covering much of the sky-much brighter than on Earth." (Quote from Brandon Sanderson - answering a question about Scadrial).