A new Google Maps / Google Places bug was reported at Google Places Help the other day.
It appears that owner responses to reviews on Google Maps show up fine for desktop users but not for iPhone, Android or smartphone users.
Here is a screen shot of this maps listing which clearly has a owner response to a review on the desktop version but it is completely missing from the mobile template version.
Vanessa from Google responded to the issue in the Google Places Help forum saying it is a bug and they will work on it. She said:
Hmmm interesting! I've sent this along to my team, looks like a bug.
Thanks for reporting this.
Forum discussion at Google Places Help.