There seems to be some confusion here. What the above posters are referring to are “foreigners married to Taiwan nationals.”
Under Taiwanese law, a “foreign spouse” is considered to be a foreigner married to a local Taiwan citizen. Hence, a “foreign spouse” with an ARC based on marriage does not need a work permit according to Article 48 of the ESA, as of May 2003.
If you and your wife are both foreigners, that is another situation entirely. Assuming her residency is based on your residency, then if she wants to work she still has to go through the normal route of getting a work permit like any other foreigner . . . . . . there is no preference or special treatment due to the relationship to you.