[cabmandone]

Why not just pull a few wires from the main panel into the garage? Two 20A circuits for plugs and one 30A circuit for the compressor. 10/3 w ground for the compressor and 12/2 w ground for the plugs.
For pig tail I'd go hot to the compressor meaning wire from your main panel to the compressor at a J box.

Strike that! You're only 7.5 FLA to at 240V so a 15a 240v circuit should be fine. Must be a small compressor? There are wire sizing calculators for length of run. You just want to make sure your breaker is sized for the wire so you don't have a breaker size greater than the amperage the wire is rated at for the length of run.