I wanted to suggest briefly that there is an interesting, if subtle, tension between these two formulations. Lukács takes commodity fetishism to refer to a situation in which “a relation between people takes on the character of a thing” (emphasis mine). Marx speaks, instead, of a situation in which producers’ relation to “the sum total of their own labour” is expressed in terms of “a social relation… between the products of their labour”, and in which “a definite social relation between men… assumes, in their eyes, the fantastic form of a relation between things” (emphasis mine).
Among the different paths these concepts then travel: Lukács describes social relations taking on a “phantom objectivity”, and goes on to argue that this is related to the ascendency of formal, abstract and instrumental forms of perception and thought; Marx, by contrast, draws attention to an apparently mystical process in which material things are constituted as the bearers of supersensible social properties. Lukács speaks as though the spread of market relationships generates “reification”; Marx instead argues that the fetish results from “the peculiar social character of labour” - something that he does relate to the spread of market exchange, but only en route to discussing how commodity-producing labour possesses a dual character, split between human energy actually expended in concrete “sensuous” labouring activities, and “human labour in the abstract” - a collectively-enacted, supersensible pool of homogeneous, undifferentiated “labour” in which concrete labouring activities partake, more or less successfully, at the point that their products enter into relations with one another during market exchange. Lukács’ reification picks out the hypertrophic and cancerous expansion of a one-sided, abstract and form “rationality”; Marx’s fetish picks out a sensuous material world “haunted” by supersensible entities.