The 16F88 doesn't have a hardware Master I2C. It's got Slave & Master SPI, but for I2C it's only Slave. You have to hard-code (i.e. use your basic commands for s/w I2C) the I2C master on this one.

See the datasheet...pg 89 shows the only master option as "firmware controlled" (meaning it's not in hardware). Besides that, your SSPCON settings were for SPI master, despite your comment indicating I2C.