Is there any advantage to getting an 130 amp alternator vs 90amp?

Definitely not. It will only put out the exact same amount of current as the 90 amp to meet the needs of the electrical system. It will not charge the battery any faster or raise system voltage. All that is increased is the maximum capacity that is rarely needed.

A larger generator is like putting a larger capacity pump on your lawn sprinkler system. The water isn't going to flow any faster if the pressure is the same.

There actually can be a drawback to installing a larger generator. Different size fuses or fuse link wires are installed at the factory to match the generator's output. If you have a load test performed to test the maximum capacity of the generator, that higher than normal current can burn open the fuse.