Acknowledged, by whom? As far as I know people in the logic programming community have no trouble recognising datalog as a logic programming language, be it evaluated bottom-up or not (you can still evaluate a datalog program top-down, by resolution, as if it were a Prolog program without "compound" terms) (a.k.a. functions).
Indeed, I get the feeling that the primacy of Prolog as the logic programming language has waned. If you look at back issues of ICLP* proceedings you'll find plenty of work that is nothing to do with resolution- namely, Answer Set Programming, which is wildly popular.
I tend to think it's mainly the database community that kind of ignores the logic-programming nature of datalog.
Oh and btw, when I talk about datalog, I mean definite clauses without functions, not the aberrant syntax in the article above. I'll never understand why people do that.
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* ICLP is the International Conference on Logic Programming.