Responding to papers which reinvent ideas without citing them A few months ago a very well-known (and controversial) authority in my field published a theoretical model of a phenomenon that one of my collaborators addressed many years ago. Interestingly, the paper does not reference my collaborator's work at all, even though the authors of this new paper are well aware of it, and have carefully cited "around" it.

My initial response was not to respond, but then I noticed striking similarities between specific paragraphs in the paper and my collaborator's work. The authors reach the same conclusions as my collaborator, but using a model they have developed. Though it doesn't qualify as plagiarism, it annoys me when "new" ideas are proposed without crediting those who originally proposed them. Of course this happens all the time, but I have never been in a position to respond.

My question is how should I respond to this paper, and whether I should respond at all. My collaborator has ceased publishing in this field, and was not interested in responding (but wouldn't mind if I did). Otherwise I have had mixed responses from colleagues, everything from "it happens all the time", to suggesting that I write to the authors or the editor of the journal. Another point to consider is that the senior author is on the advisory board of the prestigious journal the paper was published in.
From what you have described, it is unlikely that the author's decision to omit mention of the previous paper would constitute any breach of the journal's policies, or any violation of academic integrity requirements.  You have stated your assessment that this is not a case of plagiarism, notwithstanding some similarities between the present paper and the previous paper.  If that assessment is correct then you are really just talking about a decision by the author to omit mention of a previous paper, which is a decision that is within his discretion as a researcher, and which has gone successfully through peer review.

Since there is no evident breach of policies or academic integrity standards, the journal is unlikely to change the article unless its authors request an addendum.  You could either write to the authors suggesting this, or you could try to publish your own "letter to the editor" supplementing the information in the recently published paper by mentioning the previous work.  A letter to the editor could draw attention to the omitted work in a respectful way, noting the similarities of the ideas in the two papers, and noting the way in which the present paper formalises the previous idea with a new model.  That would make a nice supplement for readers who are unfamiliar with the previous work.  Of course, there is no guarantee that the editors would publish it, but if you feel strongly about this, it might be worth a try.  If you can say something valuable about the connection between the two papers then the editors might decide that it is a worthy supplement.