After I developed occasional acid reflux, I have been putting cream or half & half in my coffee to neutralize most of the acid. And that resulted in me thinking I also needed some sweetening. So this morning I put a splash of half & half in the cup and returned the bottle to the fridge, poured the coffee, added sweetener, went to the fridge and added a splash of half & half, went to answer the phone, went back to get my coffee and was about to open the fridge to get the half & half when the light bulb finally switched back on.
I had to take one of those on line intelligent tests that lets me score at mensa level (don't laugh) and then I felt reassured.
Actually, from what I've read, dairy tends to be slightly acidic. Less so than coffee, perhaps, but not on the alkaline side of things. If you use almond milk or soy milk, I think those move the body's pH toward alkaline, and would better counteract the acidic effect of coffee than a dairy cream.
Oddly enough the right kind of acid does counteract other acids though. For instance at least mild acid reflux often settles right down when a glass of milk is consumed. I think it is the calcium that counteracts acid in coffee though so skim milk would provide more of that than the same amount of half & half or cream. (Doesn't taste nearly as good though.

) And a tablespoon of apple cider vinegar and a tablespoon of honey dissolved in a cup of hot water and drunk can do wonders to calm down unruly acid in the stomach along with a lot of other holistic benefits. Don't ask me for the science because I can't explain it. But it does work for many.
I think it would be a difference in effecting the body vs counteracting the effects of the coffee. ACV doesn't counteract or neutralize acid in the body, but it may lead to a reduction in acid production in the stomach, or perhaps some component of ACV changes the way portions of the digestive system function. It wouldn't increase pH levels, but maybe something about it causes your body to increase pH levels.
It also could be that there is a difference between the overall pH levels of the body and just the acid issues that arise from reflux; reflux might cause problems regardless of whether your blood pH is low, in other words.
As long as you feel fine with cream in your coffee, and your doctor hasn't told you to stop, it doesn't seem like anything to worry about.

If you do ever find yourself having acid issues, though, you could try switching to a less acidic form of milk/cream in case it helps.