I tend to take "drinking dreams" as a serious warning. To be sure, some are just a dream and don't mean anything. Other times though, they've were absolutely a warning sign that the way I was behaving and the things I was thinking/saying/doing in my life were NOT congruent with the life in recovery I wanted to live or even thought I was living. Denial and delusion can be very sneaky.
Knowing for real whether it was just a dream or a warning doesn't usually come until "later." Sometimes that's days, or weeks..... sometimes months. When I have them now, I take what I believe to be the most mature view I can take and assume they're a warning. If I assume they're a warning, make some positive changes and it turns out that it was really nothing to sweat..... good.....I'm better for the changes I made. If it was a warning, NOT making those changes would result in disaster. So whatever the "truth" may be at the time, I treat it seriously.
When I've had them AND I can easily spot some areas in my life where I'm not in harmony with what's happening, the people around me or even when it's just internal stuff I'm struggling with... then I pretty much know it's a warning and that the warnings have progressed to the point where I'm now dreaming about them AND remembering the dream. For me, it's definitely time to do some honest reassessments of where I really am in my recovery - and that has, every time I can think of, turned out to be a quite different place than where I "thought" I was at the beginning of my investigation.