Save It depend on where you departure. If you departure from Mainland China (except for Hong Kong, Macau, Chongqing, Nanchang and Kunming), your wife need a Taiwan Travel Permit for Mainland Chinese Residents with an Individual Tourist Endorsement (only residents with hukou or residence permit of 47 cities are eligible for non-group Tourist Endorsement, and Group Tourist Endorsement can only pass through China Immigration Inspection with the tour guide and group). Also, pay attention to the checked baggage status of your flights (usually the checked baggage cannot be directly transported to the final destination if you take flights combined with China Eastern Airlines and China Airlines, so your wife need a Exit&Entry Permit in order to claim the baggage and re-check it, but baggage is usually directly transportable if you fly with the same airline company both for the flight arriving to and departing from Taiwan). If you fly with Star Alliance airlines (Air China, EVA Air, United, Air Canada, etc.), the baggage is usually not a problem. But if you fly with DIFFERENT SkyTeam (Delta, China Eastern, China Airlines, Air France, KLM, etc.) or other airlines (China Southern, Sichuan, etc.), especially when China Eastern Airlines (including Shanghai Airlines, a subsidiary of the airline above) is the first segment, baggage could be a concern. Remember that UNI Air is a subsidiary of EVA Air; Mandarin Airlines is a subsidiary of China Airlines. Also, never confuse China Airlines (CI/CAL, based on Taiwan) with Air China (CA/CCA, based on Mainland China).
Save It depend on where you departure. If you departure from Mainland China (except for Hong Kong, Macau, Chongqing, Nanchang and Kunming), your wife need a Taiwan Travel Permit for Mainland Chinese Residents with an Individual Tourist Endorsement (only residents with hukou or residence permit of 47 cities are eligible for non-group Tourist Endorsement, and Group Tourist Endorsement can only pass through China Immigration Inspection with the tour guide and group). Also, pay attention to the checked baggage status of your flights (usually the checked baggage cannot be directly transported to the final destination if you take flights combined with China Eastern Airlines and China Airlines, so your wife need a Exit&Entry Permit in order to claim the baggage and re-check it, but baggage is usually directly transportable if you fly with the same airline company both for the flight arriving to and departing from Taiwan).
If you fly with Star Alliance airlines (Air China, EVA Air, United, Air Canada, etc.), the baggage is usually not a problem. But if you fly with DIFFERENT SkyTeam (Delta, China Eastern, China Airlines, Air France, KLM, etc.) or other airlines (China Southern, Sichuan, etc.), especially when China Eastern Airlines (including Shanghai Airlines, a subsidiary of the airline above) is the first segment, baggage could be a concern. Remember that UNI Air is a subsidiary of EVA Air; Mandarin Airlines is a subsidiary of China Airlines. Also, never confuse China Airlines (CI/CAL, based on Taiwan) with Air China (CA/CCA, based on Mainland China).