In Season 2, the team visits Pylea where they encounter Covenant of Trombli Holy Books in the episode Through the Looking Glass.
It's very brief, but we see the holy books:
The team does notice the coincidence, but it isn't really spoken of again. From the transcript:
Gunn: "Like one of them priests the host was talking about. These books belong to them, right?"
Wesley closed the middle book and sees that it has the head of a male sheep engraved on its cover.
Cordy: "Well, yeah."
Gunn: "Look, you're the one going on and on about how you're the princess. Can't you just make them translate 'em for us?"
Wes closes the second book. It has a wolf's head on the cover.
Cordy: "I guess I could. Yeah. Why not? Princess, not really taking a vote, is she?"
Wes looks down at the images on the covers of the three books, rearranges their order.
Cordy: "I'll make a decree."
Gunn looks down as well: "Wolf - ram..."
Wesley: "And hart. - I'm not sure the priests can be trusted."
Whether or not it was a retcon at this point is unclear, since Wolfram & Hart first appears during the first season of the show, but the idea of Wolfram & Hart being a portmanteau was being established long before season 5.