high voltage Buck-Boost converter
In general, this sort of "universal" AC-input power supply is going to be done as two separate stages: a boost converter (optionally including power factor correction) that creates a loosely-regulated 400VDC bus, and then a buck regulator that converts that to your output voltage, using a transformer to achieve isolation from the mains.

As an alternative, you might consider purchasing an off-the-shelf switching power supply rated at, say, 24V @ 1A (this would give you your isolation and most of your required certifications) and then use a relatively simple boost regulator to convert this to 112-115V @ 150 mA.