The larger yoga centres in Ubud all do international standard teacher training programs (usually 200 -300 hours). Take a look at the post for yoga in Ubud in the link below. The list below covers most places where you can stay and do daily wellness activities including yoga. They are many and varied in style and budget. There are also lots of hotels and resorts that offer wellness packages and/or free yoga which aren't included here; cheap and cheerful Honey Guesthouse, a mid level option like Swasti Eco Cottages, and the more fancy ones include Como Shambhala, Sankara, Four Seasons and Maya Resort.
Soulshine A lovely spot relatively close to Ubud with a fantastic food and great view. Soulshine does various week-long retreats, plus daily yoga and other wellness sessions. The retreats are pricey at around US$4000, and overnights stays are about $200. Book.
Bagus Jati 5 Hectares of hillside gardens overlooking rice fields and jungle make this a spectacular spot for a health and wellbeing retreat. There are loads of accomodation options and the retreat offers programs from 2 nights which include twice daily yoga, spa treatments, and healthy food from US$565. Book.
Anand Ashram The ashram experience is a minimum 3-night stay in a very Indian-looking place in north Ubud. Casual visitors are also welcome with a booking. Website
Blooming Lotus. Yoga and meditation 4- and 7-day retreats plus daily classes and teacher training. Book (currently on special at US$300 for the 4-day retreat)
Amrtasiddhi An Ayurvedic healing centre in Nyuh Kuning village just south of the Monkey Forest. They offer healing, rejuvenation, and detox and weight loss programs from 7 days with accomodation and food, and also individual consultations. It's not cheap. Book.
Ashram Munivara This is a teacher training ashram, although they do have some daily yoga and personal retreats, but there is only one option available at the moment. Book
Gokul Yoga A gorgeous spot in the jungle, Gokul offers weekly retreats (from US$250 depending on room type) that include classes, massage, daily means and other activities. There is also a 200 hour teacher training course and a cleanse and a full immersion yoga retreat for experienced teachers. Book