The short, yes. The long answer, almost always yes. And looking at the extremely low rate of reactions, definitely yes! 

Generally speaking, the consistently effective properties of propolis as immunostimulating, anti-inflammatory, antiseptic agents are inherently safe no matter where it's sourced, complementary to alternative medicine, as well as orthodox medicine. Following are excerpts from 2 recent studies:

Propolis, Abundant Source of Beneficial Effects for Human Health

Propolis is a natural product, collected by honeybees Apis mellifera, from various plant sources. Propolis is extensively used in foods and beverages because it improves human health. It contains more than 300 natural compounds such as polyphenols, phenolic aldehydes, sequiterpene-quinones, coumarins, amino acids, steroids and inorganic compounds...

Propolis exhibits a broad spectrum of biological and pharmacological properties such as:

• antimicrobial 
• antioxidant 
• anti-inflammatory 
• immunomodulatory 
• antitumor 
• anticancer 
• antiulcer 
• hepatoprotective 
• cardioprotective
• neuroprotective  

The chemical composition and beneficial properties of propolis vary greatly depending on the phytogeographical areas, seasonal collection time, and botanical source. Polyphenols found in fruits and vegetables are beginning to receive increased attention due to their vital role in protecting neural cells from oxidative stress and neuroinflammation associated with normal aging and chronic age-related diseases...

Is Propolis Safe, Alternative Medicine?

...Propolis is produced worldwide and honeybees use the flora surrounding their beehives for its production. Therefore its chemical composition may change according to the flora. The phenolic and volatile fractions of propolis have been revised in the present study, as well as some of the biological properties attributed to this natural product. An alert is given about the need to standardize this product, with quality control. This has already been initiated by some authors, mainly in the propolis from the poplar-type. Only this product can constitute a good complementary and alternative medicine under internationally acceptable quality control…