Due to my current situation with work and study at the moment, i am only able to conduct two track workouts a week. Albeit not ideal, i include tempo on the same day as my speed workouts.
My question is should i use the tempo as part of an extended warm up such as i.e 8 x 100m, drills, dynamic stretching and so forth or do 6 x 100m for warm up, then hit the main workout and conclude with 4-5 x 100m?
Your opinions would be greatly appreciated 
With only 2 sessions a week you can pretty much kill yourself because you have long enough to recover. Iād do a little during warm up and then more at the end of the session. Really depends how much time you have.
While some tempo can be used as part of the warm-up, I think you should also include some low intensity workouts between speed sessions. If tempo running is not feasible due to scheduling constraints, substitute something else, such as calisthenics and/or med ball circuits. You can get in a solid workout in 20-30 minutes this way and it allows you to distribute the work over more muscles groups.