TMP461-SP: What's the difference between a pointer register and address?

The Address is the I2C address, which applies to the TMP461 on the bus. In the Figure it's 0x4C, for A0=A1=Floating. [Ref Table 4] 

The Pointer register is internal to the TMP461, and is an index into the register map [Ref Table 5] for the register being read/written.

The I2C address doesn't change at run-time (in general -- there are some unusual applications). The Pointer changes routinely.

[Disclaimer: I've never used the TMP461, but the terminology is standard(-ish).]