Can my foreign wife get a long-term visa in Thailand while I have a Non-B visa?

It may be better for you to talk to your employer to support your wife's visa/extensions first. Your wife needs documents from your employer to apply as mentioned.

So you have a Non-B visa/extension for legally working here. Your foreign wife should be able to get first a 90 day Non-O visa based on marriage to a foreigner legally working here and then a year extension that matches yours for the same reason.

You should go to your immigration office and get the hand out listing the requirements as far as documents from your employer, marriage certificate, etc. She will also need to have a minimum number of days left on her current visa exempt or tourist visa entry stamp (usually a minimum of 15 to 21 days) to apply for the 90 day Non-O visa at the immigration office