[RobbyS]

No, Omar is saying that there is nothing except the taste of the wine he is drinking. except maybe the intoxification that is a foretaste of final oblivion.

[Hound of the Baskervilles]

Woah! So many pithy comments!

[GSlob]

the remainder of that quatrain gives a lie to your interpretation:
"Don't wonder at the bitter taste of wine -
My bitter past is tasting the same way"
[I had to do the translation of the second order, as I do not read farsi and do not have access to an English translation. From the one I had, I did it almost verbatim, except for the last line, for I had to preserve the meter as well]. So there was a lot more to his wine than its simple taste.