Blooming on chocolate occurs when the tempering process is not carried out properly or when there has been exposure to moisture. When chocolate has not been tempered properly the bonds in the cooling process do not crystalize. This leaves the fat and the chocolate separating, therefore creating a bloom on the finished product.
If the chocolate has been exposed to moisture or perhaps stored in the fridge, this will cause condensation creating a separation in the sugar molecules; creating a bloom.
Yes, blooming chocolate is 100% safe to consume. There is no difference in taste. One might find that the texture and appearance may differ.