VPIP over different poker variations

[AlwaysWrong]

In general, as far as I know, the generally accepted way to play poker, any kind of poker, is tight-aggressive. In limit hold'em, it is advised that you voluntarily enter the pot somewhere between 15%-25% of the time. I don't know much about any other forms of poker. What I'd like to know is:

Is this a universal number that applies to all forms of (limit) poker with the same betting structure? For Omaha hi/lo should I play 15-25%? Omaha hi? Pinapple? Etc. What about something like 1-card hold'em with an extra card on the flop? What factors determine the optimal frequency for entering a pot?