Depends on the company.
Don't know about international travel, but most airlines will provide domestic passes (Space A) to interviews. Some companies (NJA used to don't know if they still do), will send positive space tickets... others will offer discounted fares, while some won't offer any form of assistance.
My former employer (ACA) used to offer free tickets on our flights and reduced rate travel on our partner (UAL). IIRC it was $125 roundtrip from anywhere in the US.