Andrew McGowan Points to the Marcionite Use of Wine in their Eucharist

Well, it's Ephrem who actually does the reporting.  McGowan is one of the best interpreters of information from Patristic sources because he actually tries to balance the evidence in the context of multiple witnesses.  The example of Tertullian's reference to bread being the 'symbol' of body of Christ.  We have already seen that von Harnack rightly points to this as being the original Marcionite reading.  It is worth noting that Ephrem makes a similar Marcionite conception regarding the wine as the 'symbol' of the blood of Christ as we read in a footnote in McGowan's Ascetic Eucharists Food and Drink in Early Christian Ritual Meals where we read:

Nor does it [the Marcionite Eucharist] seem to be wineless, despite the indications that early Marcionites refused wine (see further below). Earlier in the same hymn Ephraem wrote: 'The assemblies of the "deniers" do not have the true blood of Christ . . . they have only an image which is similar, because they do not recognize the real body of Christ' ( Hymn. contra Haer. 47. 1).

I think it is quite reasonable to assume that the Marcionite gospel - already identified as a form of the Gospel of Mark with things 'added to it' (Philophumena 7.18) - is one and the same with Clement's Alexandrian 'mystic' gospel of Mark. Over and over again I see reasons to believe that Clement's Alexandrian tradition was neo-Marcionite. Just look at the last post where we demonstrated that of the New Testament literature only the Gospel and the Apostolikon constitute 'the Scripture' of the Alexandrian Church. This can't be coincidence. Clement may have been willing to cite material from Acts, the Apocalypse of John and other texts, but they weren't canonical Scripture for his tradition.