I picked up a 7' fast action penn allegiance inshore baitcasting rod on clearance for $30 at walmart.  Will this rod be solid for rainbow trout and bass fishing or should I return it and look for something else?

I'm not familiar with that rod.  I always look at the line and lure rating as well as the action when determining the use of a rod.

I would hazard a guess that it's likely a little heavier than desired for bass and trout.  What are the rod and reel specs?

It's 7'; 8-15lb line; 1/4-5/8oz lure

 

The reel I have to use with it is a Bass Pro Tourney Baitcaster: 12lb/120 yard line.

It sounds like a typical medium and will work fine.