Here in California a apprenticeships are state mandated by the Labor Commissioner meaning the curriculum and the hours are exactly the same, so you can sign a union agreement or use someone like ABC for your apprentices.
Most prevailing wage work requires certified payroll each week to be submitted with your billing they do this to qualify the wages are in fact being paid. If you get the job send a practice certified payroll document (from the general conditions of the contract docs) to work out any bugs, the General, Client, all involved will appreciate this because this will help billings go smoothly.
The union contractor actually have an advantage over the non-union in that they pay the wage and their burdens are equated from the gross wage the employee receives, most of their benies are tax sheltered. A non-union company usually does not have any benies set up as an hour bank or some shelter and they do have to pay these so they usually pay them to the employee and therefore their burdens (taxes) are greater
For estimating bid the base wage plus total wage benefits multiplied by your burdens (taxes, insurances - the stuff you have to match on your employee's taxes and maybe some additional management for payroll/direct labor burdens that sometimes are accounted for as OH). Your burden multiplier - not overhead - should be around 75% +/- for your journeymen. If your area is like California you'll be wasting your time to bid without apprentice wages because you should be high, if you not and you get listed GET BUSY and good luck! You should bid an upper level apprentice wage, the benies are slightly less but your burden multiplier should be 80% +/-.
Using journeymen and apprentice wages you simply need to bid the mixture or their time like 60% journeyman and 40% apprentice, so if your total bid hours are 10,000 then 6,000 is at journeymen wage and 4,000 at apprentice wage the two combined need to be as close to reality as possible but do cover yourself here. If you look at your total bid with 100% journeymen wages compared to a crew mix you'll see a substantial difference.
Remember a clich?: mess UP don't fall down, if your not sure about the market hold the line and you will use more overhead than normal. Always get your bid results from all your contractors after bid opening, it's public knowledge and it will help you decide your markets.
