You would connect the Bolt module to the raspberry pi, just as you would interface any other uart capable controller with the Pi.
You can go through the following link to understand how to use uart on the raspberry pi 3
Once done, you will have to connect the tx, rx, gnd and 5v pins of the raspberry pi 3 to the rx, tx, gnd and 5v pins respectively of the Bolt module.
Then you will have to write a uart communication program on the raspberry pi 3, such that it can take commands from the Bolt module.
You can go through the following link to understand how to write the required code for the Pi.
Once done, you can receive commands from the Bolt module.
To send commands to the pi you will need to use the UART API for the Bolt module documented in the link below.
If you want to log data to the Bolt cloud, then you will need to write a program on the pi which waits for the command "RD\r" (That's Capital R, Capital D followed by a carriage return) from the Bolt module, and immediately sends UPTO 6 comma separated values to the Bolt over the Uart.
Configure the product to which the device is linked to as UART input with the same number of monitored values as sent by the PI, and the data will be logged to the Bolt cloud.