Multiple Arduinos to a datalogger/phone?

Hello, I have two Arduinos currently set up, one to read RPM of an engine and one to read drivetrain rotational speed. I have them all functioning properly, however I find it frustrating that (using ArduinoCommander on my Android Tablet, connected via a BlueTooth Shield) I can only connect to one at a time to display information. I would like to be able to read these two on one single unit (another Arduino maybe?) and have that communicate with my android Tablet. I want to be able to datalog the information as well with whatever methodology I'm using to connect both Arduinos together. (I'm using 2 SD Shields, one to both Arduinos for this, I would rather just have to use one. The same goes for Bluetooth shields.)

Is this a feasible project, and if so how would I approach it? Or am I just being too hopeful?

Lumker:
I would like to be able to read these two on one single unit

Why don’t you use a single Arduino to read both signals? That would seem to solve all your problems, as well as halving your hardware costs.