Just searched Google and they do produce their own wine, could be interesting

We stay in one of the Iberostar hotels outside PDC and they always serve (good quality) Spanish wine. I would imagine it may well depend on the hotel chain ... Iberostar and RIU are Spanish companies so maybe this influences the wine served. Have to admit in all our years of going to Mexico we have never experienced their wine ... just their Tequilla and beer

I have stayed at a Riu and Crown paradise and the red wine was horrible at both!! Just stick to the beer!! Its nice though if you eat out.

Just returned from the Sandos Playacar Beach Resort. Some of the wines served here are very good, all bottled, no bulk wines. Our favourite red and white were both Mexican from Baja California and both the same brand, XA. They both retailed locally for around $8. Also available were French and Spanish. One Rioja was retailing for $19 at the airport. I was really surprised at the quality of food and drink at this hotel, I could become an AI convert but doubt they are all this good.

when we were ther it was mostly Californian and Spanish bottled wine

Mexican wine is available but Tequila Centanarian is best (and costs an arm and leg but worth it)