This is a first class top restaurant in a well-known American setting. Business casual is about as dressed down as you might feel comfortable. Being a golf course restaurant, you can expect some casual golf attire at the restaurant. You will not be turned away. It really has to fit your comfort level with the other customers.
This is a high end restaurant, in a nice Hotel, next to the best golf course in San Diego. Yes you should dress appropriately
For lunch it is more open collared shirts and slacks, but I always feel better about wearing a sports coat for dinner, and when in the mood, a tie, if my wife wants to be dressed up. Never a suit. It is, after all, a lodge.
There is no official dress code, after all you are in San Diego, the casual capital of leisure. I would follow your own comfort level, i.e., how would you dress at an upscale resort anywhere in the USA? Because of their golf course you will see every level of dress, they are very accommodating at both the Lodge and the restaurant. The idea is to have a good experience and to enjoy both the food and the environment. You will find San Diego never to be stuffy or demanding. It is really a spoiler to live here !!
Not really but it's a very nice restaurant and would not advise going in shorts and flip flops. For men in the evening a long sleeve showier and slacks would be fine. There is a very casual restaurant downstairs where you would be comfortable in golf wear.
Get quick answers from A.R. Valentien at The Lodge at Torrey Pines staff and past visitors.