Combining two different voltages into one regulated voltage at higher amperage
You don't need both supplies.  9V at 100mA is 0.9 watts.  You need 3.3V at 150mA or .495 watts.  A switching supply that converts the 9V to 3.3V will certainly be efficient enough to give you the 150mA that you need.

Look at the TPS62130 from TI for example: 

http://www.ti.com/lit/ds/symlink/tps62132.pdf 

There are countless other options from TI, Linear Tech, ON Semi, Maxim, Intersil, etc.