Our recommendation: if you are in the Mendoza province for the wineries/ posadas stay out of Mendoza city.
Located near Maípu and the wineries, the Posada Cavieres is an excellent choice. The owner and host, Hans, is very friendly and hands-on. He helped us by identifying the wineries (bodegas) we should visit. We could also rent bikes on the spot (not very comfortable but okay) and visit Maípu's establishments (Carinae, Laur olive oil, Trapiche, Tempusalba and more). The next day Hans got us a taxi to drive us around Lujan de Cuyo.
The Posada is a very relaxing place, rustic with nice hammocks, lounge chairs and swimming pool with two friendly dogs. We could buy a nice wine bottle and have it on the porch with home made dinner - the host cooked for us the two nights and it was excellent. For breakfast, nice fruits, locally made jams, ham, cheese, fresh bread and coffee/tea were served. Great value.
No negative. Note that the Posada has a community feel (that we loved) but if you don't want to interact with other guests - examples: share breakfast table with them, share the pool area, enjoy a wine bottle with other travellers during happy hour - you might not enjoy this place as much as we did.