Basil Pesto and Cream Cheese dip
As long as the whole dip is/was kept in the safe temperature range (under 40 °F / 5 °C), I don't think you will have a food safety issue.  Remember, time out of refrigeration (well, technically in the danger zone of 40~140 °F / 5~60 °C) is cumulative.  How was the dip served the first time?  If the cream cheese (a "potentially hazardous" food, much more so than parmesan or pesto) sat out at room temperature in the danger zone for 2 or more cumulative hours (4 at the outside) you should discard it.

Other than the food safety issue, there may be some minor interaction among the ingredients, but that will be more a palatability issue, not a safety issue.   The flavor might even improve.