If EROEI < 1, then there is no meaningful cost of net energy - the denominator is negative. If EROEI > 1, then it's a potential energy source, and what's interesting is the cost of net energy.

Re running buses on fuel: any bus will run at less than 100% efficiency, so its EROEI is less than 1. As for its fuel, an EROEI < 1 doesn't necessarily matter, because now we're talking about energy vectors rather than energy sources.

A fuel with EROEI < 1 can be perfectly viable, if it's converting a less portable energy source into a more portable one. For example, synthetic hydrocarbons created from grid electricity have an EROEI < 1, but turn grid electricity into a fuel that can power planes, ships and HGVs. And once that process is cheap enough, it's a much better option than oil.

Italian wine is irrelevant. Or, more specifically, EROEI is irrelevant to it. The two limiting factors on Italian wine are that its water content is too high for a fuel, and the total possible production isn't very high.