I don't know what the official advice is.
I started DD off on apple puree with a touch of cinnamon; her second food was pear with vanilla. I wanted it to be interesting for her : ) By the time she was 7 months, she'd had nutmeg, cumin, coriander, turmeric, basil and mace as well. None of these caused a problem and she seemed to enjoy the flavours. Since then we've added more herbs and spices.
When we started meat (at 6.5 months, though she wouldn't actually eat it till 7.5 months really), all her little casseroles had onion in, and some had garlic. I think they did make her a little windier, but not enough to cause her discomfort. If I were to try those with a younger baby, it would be in very small quantities and not in the evening, just in case!
Martina, we've just hit the nine month mark, and I'm starting to just hand her random stuff out of the fridge to see what happens. It's such fun, I love this stage : )