I imagine the Philippians are simply reflecting the influence of the Americans over the last century. Why they dropped the 120 volts and only use 240 may just be because it is a more efficient use of the copper.
As for the voltages. FPL says this in their service standards
The state of Florida requires that utilities normally operate within a range of plus- or minus six volts (114 - 126) from standard voltage (120).
So you see all of those voltages are within the nominal 120.
