Just saw that there is now a Hawthorn Suites in Mendoza City now
There was a Sheraton under construction when I was in Mendoza about 10 months ago. I'm surprised it is still not listed on the SPG website. BTW, I took a look at The Park Hyatt when I was there. Nice public spaces, but I did not see a room. Seemed out of place in Mendoza... which struck me as a place that had seen better days.