] "Vienne" is pronounced "Vyen" (0r Vjen with a soft J!), with hardly any Y sound and the stress on the final syllable, so it may not particularly help a Francophone. There are, in fact, a river (a tributary of the Loire) and Département of France with that name.

Interesting about the vowels, but I was thinking more of the 'W,' which in German has a 'V' sound -- so writing the name of the city with a 'V' would be a clue to non-natives as to at least some of the pronunciation.

The name of Wien comes from the Roman fort that was established at that location before the 400's, in Latin 'Vindobona,' referring to the good vineyards the Romans found they could grow there. Today there are still vineyards outside the city. Do you think the name of the river might also derive from early Roman vintners?