There are many factors that affect the shelf life of chocolate bonbons. The 5 most important are:
Since microorganisms need water to grow, it is of course important for the shelf life of chocolate bonbons that there is an “environment” within the bonbons where the proportion of active water is limited. This makes the conditions for microorganisms bad.
Sugar in the filling helps to bind the water in the filling, and thus sugar helps to provide a good shelf life for the chocolate bonbons. In the chapter "Sugar" in my e-book "CHOCOLATE BONBONS - a practical guide" you can read more about the properties of different types of sugar in relation to shelf life, taste, and texture.
By letting the filling crystallize in the shells for 8-10 hours at 16-18°C before capping, you also achieve a longer shelf life of the chocolate bonbons than if you simply cap the bonbons immediately after filling.
A tight cap of the bonbons is of course paramount for shelf life. If some of your chocolate bonbons have not been capped properly, I suggest that you eat those first, as their shelf life will be very limited.
The optimal storage temperature for chocolate bonbons is 16-18°C. If the bonbons are stored at a higher temperature, the shelf life will be significantly shortened.
Provided that the bonbons are stored at an optimal temperature (or cooler), that the work is carried out “cleanly” at all stages of the chocolate process, and that the chocolate containers are properly closed, all the fillings that I give you recipes for in "CHOCOLATE BONBONS - a practical guide" have a shelf life of 1-2 months.