Bowling was fun to a certain degree, you were fighting against an oponent and you had to calculate it right. But most of the time you would go winning because of the AI's poor efforts at it.
It became boring due to the simple fact you would bothered every 5 in-game minutes by your favourite cousin to go do that specific activity, only that specific activity you have to do.
Sorry but one up for Yoga is the fact that Amanda doesn't hassle you every five minutes to do it. It's just there and it's pewtty optional.
I don't get how you could find yoga more interesting than bowling, yoga is linear, bowling is not. Bowling is much more diverse, and takes more skill, it's more rewarding, and to me, a lot more fun, not to mention GTA IV has AI, unlike GTA V, even in bowling they do a pretty good effort. Yes, I love the "let's go bowling" quote Roman does, but he doesn't call frequently. You know who does contact you frequently? Businesses in GTA V, they message you so often to do the same thing, and unlike GTA IV's which was random, GTA V's is scripted, so if you load your save, you might be greeted with a message from a business, how is that fun? Phones have ruined society in real life, and they're ruining games, I just want to play a game, I don't want to have to deal with repetitive issues all the time.
Oh, and at least the 'Sleep Mode' feature works in GTA IV, so if you don't want to be called by friends, you can turn it on, Rockstar didn't even make it work in GTA V, even with it on, I still get messages from businesses, yes, Sleep Mode is supposed to make your phone act like it's on aeroplane mode, so why do I still get messages? If you think getting occasional calls in GTA IV is annoying, I don't know how you're still coping with GTA V.