Has the use of the idiom "last week" surpassed the use of the correct "yester-week"?
Solution 1:
Yes.
It’s very tempting to leave the answer at that, but… some more notes.
The most cursory look at any newspaper, or around the blogosphere, confirms this answer. ‘Last week’ is common as muck, while ‘yester-week’ is virtually non-existent, and when it does appear, it’s for archaic effect.
‘Last week’ isn’t in any way incorrect. It’s had the meaning ‘most recent, latest’ for over 600 years: in 1411, for instance, the rolls of Parliament under Henry IV refer to “The last parlement…” (OED.)
As your sources point out, however, ‘last’ can sometimes be ambiguous, and ‘latest’ is often a good alternative in those cases. Talking about ‘the latest week’ sounds odd and affected, just as it did when Fowler wrote; but talking about ‘Madonna’s latest single’ is perfectly fine.
‘Yester-’ isn’t actually as archaic as we tend to think! A few examples — ‘yesterday’, ‘yesternight’, ‘yester-eve’ — are old, but (according to the OED again) the general combining form (in eg ‘yester-week’) only really shows up in the 19th century. Amazingly, even good old ‘yester-year’ was apparently only coined in 1870, by Rosetti translating Villon: “Where are the snows of yester-year?”
Finally, none of the sources you give support your implication that ‘yester-week’ is the correct usage that should be preferred to ‘last week’! The Bierce and Fowler quotes point out the illogic and occasional ambiguity of ‘last’ (note that neither of these makes it grammatically wrong); Fowler’s suggests ‘latest’ as a sometimes better alternative, but neither even mentions ‘yester-’! The OED simply points out that ‘yester-’ exists (at least, existed for a few decades) and means roughly the same thing.
Solution 2:
I think you are misinterpreting Fowler. When he says "many idioms militate against it (last Tuesday; last year ; for the last fortnight; on the last occasion ; as I said in my last)", he means that these are the only correct forms, even though they clash with certain expectations of logic. Burchfield agrees: "In many idiomatic phrases last is still the only possible adj. of the two: = most recent; next before a specified time ( last Christmas; last week)".
The fact that some idiom is illogical or ambiguous does not mean that it should be changed; indeed, it should be kept here, say Fowler and Burchfield. I know this because I have read enough of their opinions to be sure.
I am not sure whether Bierce means to say "it is illogical and it should be changed" or "it is illogical but it is idiom and therefore we should keep it"; but his "Here two wrongs seem to make a right: we can say the week last past. But will we? I trow not." seems to indicate that he did not advocate a change of universal idiom either, illogical though it may be. He appears to say "this would be logical, but we will not use it, simply because we have long traditions of usage".
Words like "yester-week" were not even current around 1900, and now they are even less so; "last week" is and was the right way to say it. I see no other option.