So you have the following options.
Keep the 230V motor, change the wiring
of your alternator
and adjust the speed each time you wishes to run your compressor
. A hassle that can be made easier by the use of a switch. Also be aware that feeding by mistake 230V to yours 120V appliance may destroy the lot. 220, 230, 240V all the same more or less.
As suggested use a suitable transformer. Extra weight.
Replace the motor with a 2 or 4 poles 120V motor suitable for compressor duty and adjust the pulley ratio accordingly, check with the manufacturer if they can supply this option.
More delicate wire the generator at 230v 60 Hz and tap 120V to the 120V appliances
and see if it work, do not electrocute your-self. By the way 2.2kW at 220V is the same than 2.2kW at 130V only the current