Sam (or whatever your name is) ;-) 
 
When I was referring to the Mosaic law I am not referring just to the 10 Commandments. There are hundreds of commandments given the Children of Israel - many of which were dietary in nature. 
 
The Bible and Book of Mormon are equal to each other. They are side by side - not one over the other. The only thing to remember about our belief in the Bible is that we 'believe it is the word of God as far as it is translated directly'. 
 
Initially the Word of Wisdom was given as counsel, but is now a commandment. The reason? Because Heavenly Father has directed it to be so via revelation to his latter-day prophets.