British citizen, costa rican wife, apply from UK?

Hi, my wife and I are visting the UK, I'm a UK national, she is Costa Rican, we are here for 6 months only, so my wife hasn't got residency for the UK, I've been offered work in China, can my wife apply for an S1 visa here in the UK? We don't really have the funds or time to go to Costa Rica? If no, would Hong Kong be an option?

Cheers