There is no need to interpret the final log likelihood value because it has no meaning on its own. It is more meaningful to look at bootstrap values.

Roughly speaking, the final likelihood is inversely proportional to the size of your alignment (both in terms of length and number of sequences), so I would guess from your likelihood value that you have a relatively short alignment. These values only come into play when you are comparing trees made from the same alignment but with different parameter sets or with different programs. In that case higher likelihood value generally means more reliable tree.