Hi TJ guy ... sorry to respond so late...didn�t see your post until now (after jer alerted me to it)..
The concept of teaching "Business English" is pure BS as far as I am concerned as is teaching "conversation". There is no such thing as Business English. There is English. Maybe British English or American English...but English all the same. Business English is English with business vocabulary and the teacher having a knowledge of working in business and relating to various professional/working situations.
However, most places hiring don�t differentiate. Usually when they say Business English, they are looking for English teachers with business backgrounds who can comfortably talk about business situations in English with the students and can impart industry-specific vocabulary (accounting, insurance, marketing, etc.).
So, in my "business English" classes, I teach English puro y duro... and then incorporate vocabulary and situations that are appropriate for the working environment. My industry-specific vocabulary is strong in sales and marketing/public relations/finance/accounting/non-profit sector/media (television) and social work as I have worked to varying degrees in each of those sectors.
Teaching BE (as it is referred to) can be done several ways... using articles from business publications that underscore the English concept you are teaching, or using a "business English" course book. There are several here in the Spanish market...Market Leader, International Express, Communicating in Business... to name a few. I�m not particularly fond of them as it seems that they concentrate more on teaching "business" than teaching English. It�s an insult to the national sales manager when you whip out a business English book that proceeds to "teach" them business.
Most multinationals want English teachers to teach Business English and not have conversation classes. In this area the market is getting more competitive as they are seeing an economic cause/effect (due to the EU) of having employees who can communicate in English at a competent level.
Generally speaking, the consulting agencies that hire teachers for in-company classes are hiring BE teachers (TEFL certified or not and in the end...they hire the native speaker, regardless of his/her business experience...since the demand is high and the number of "qualified" BE teachers is low). The compensation is the same 15� average.
Teachers who are "hoofing it on their own" (usually the legal ones who are duly registered with the ministry of labor and are paying their own social security) can command up to 30� an hour. However, most multinationals prefer a consulting agency over a freelance teacher. It all comes out in the wash. If you are earning 30� an hour on your own...you are also putting a lot of time into marketing yourself and client retention with no additional compensation for that "work". If you are working for a consulting agency it�s the agency that�s doing the marketing and client retention...you are just teaching the class. Economics 101.
The academies hire mostly native speakers... BE teachers or not. TEFL or not. Most academies do double duty... onsite classes for the "general public" and in-company classes as they have recognized the money and demand that is in the sector.
Anyway, I think I have answered your question in a long-winded way.
If not, repost and I will try to clarify a bit more.