With a Boomkin, or Unholy DK, they have a +magic dmg Debuff that they put on the boss, which has pretty much the same effect as curse of elements, and since they dont stack, and their buffs will be up in their normal dps rotations, using elements does you no good.
Before I try to help you choose a spec that will work best for you and your raid, lets check a couple things.
As for your raid really wanting you to Shadowbolt alot, do you guys run with mages that uses scorch? Or a mage that puts winterschill on the boss? If so, your shadowbolt buff does not stack with their 5% increased crit buff. If you dont have mages and your raid needs the 5% buff, I recommend you go Heavy Demo, (a spec where you actually use shadow bolt) your current spec is tailored more towards incinerate. I have tried and tested both of the following specs and done quite well with them. Before you see that they are heavy demo, and think about dismissing them, try them. I have had great success with these specs, awesome raid buff and awesome dmg!
Note that with these specs, you will gain ~10% crit, and I gained ~500 spell dmg. All from you and your pet being active and buffed.
http://talent.mmo-champion.com/?warl...00000000000000 Without pet raid buff
http://talent.mmo-champion.com/?warl...00000000000000 With a raid buff your pet brings. (Should spec into it if you dont usually have shammies)
This is also a great link put together by a guy and posted on MMO for us, it will walk you through the multiple specs//glyphs//rotations. It is pretty well done and I use it myself.
http://www.mmo-champion.com/index.php?topic=47314.0
The big thing is getting you into a spec that benefits the most from Shadowbolt, if you are destro, you really want to be fire. Way to many wasted talents if you try to shadowbolt.
Hope this helps!