Your first exaple is correct usage for PBP. For example...

High PortA.5 ' Make pin go High (Output)

or

MyBitVariable=PortA.5 ' Transfer status of pin to Variable (Input)

or

MyFavouritePin var PortA.5 ' alias the pin

High MyFavouritePin ' Make pin go High (Output)

Your second example (as RA5) is the preferred designation in Microchips' Datasheets and is a quick way of referring to that pin although NOT a correct way to PROGRAM unless you first alias that prin as so...

RA5 var PortA.5

Now you can refer to RA5 within your program.