Symphonic means to relate to or have the form of a symphony. It can also mean relating to or written for a symphonic orchestra. There are a number of meanings that could be attached to the phrase "symphonic love". It could simply mean a love of symphony or music played by a full orchestra (or perhaps full compliment of instruments (i.e. Brass, wind etc). Or it could mean a full and complete love. A love that requires a full "orchestra" to express itself.
