Rivermaya's roots came from a band named Xaga consisting of Jesse Gonzales on vocals, Kenneth Ilagan on guitars, Nathan Azarcon on bass guitar, Rome Velayo on drums, and Rico Blanco on keyboards and backing vocals. The band was managed Lizza Nakpil and director Chito Roño. In the process of grueling practice sessions, Ilagan was replaced with Perf de Castro; Azarcon's childhood friend, Mark Escueta, to replace Velayo, as well as former classmate Mañalac to replace Gonzales. With Mañalac as frontman, the band members themselves decided to disband Xaga and form the band Rivermaya. They started putting together original songs like "Ulan", "214", and "Awit ng Kabataan" in demo form for prospective recording companies. Since its formation, the band has launched several successful albums, received numerous awards, and has undertaken several successful concerts and tours.
After the band's successful US and Canada tours, Mañalac decided to leave the band and stay in the United States.
In 2002,after living in Los Angeles following the Rivermaya tour in America, Mañalac returned to the Philippines. His former bandmate in Rivermaya, Nathan Azarcon, introduced him to Ira Cruz and Vic Mercado. Later all of them joined together and formed the band. Since then, the band had launched four successful albums, and received numerous awards.
Rumors were initially spreading on January 10, 2011 after KC Montero tweeted on Twitter that the band has decided to call it quits. On January 11, 2011, Mañalac published an official statement in the band's official website. He said, "As a group we've come to a point where you have to trust your gut, your heart and your head and accept that all things change. The hardest part as always is to know when to pack it up and part ways." He further said that, "We've learned that this journey is not only about us but includes all who came along for the trip. Family, friends and of course our front row believers who were there for the best reason of all. To simply listen. So it didn't come easy winding down to this decision. So here we go. IT'S OFFICIAL. THE BAND. IT'S OVER."
2011–present: No Water, No Moon and The Voice of the Philippines
In 2012, Mañalac released his debut album, No Water, No Moon, under the label of PolyEast Records. The album consists 12 tracks with "Questions" as its carrier single. The album reached gold record in February 2013 after selling more than 7,500 copies.
In January 2012, Mañalac joined ASAP 18 as a mainstay cast and a performer in the show.
On February 10, 2013, during an appearance on the last episode of Sarah G. Live, Bamboo Mañalac hinted that he would be working with Sarah Geronimo after they both finished performing a production number together. On February 14, 2013, ABS-CBN aired a promotional plug during the airtime of the pre-primetime television dramaKahit Konting Pagtingin, confirming Bamboo Mañalac's stint in The Voice of the Philippines as coach and judge. In an interview made by ABS-CBN News, Mañalac provided a statement regarding his stint on the show, "I'm ready to be a coach. There's a time for everything and this is it." When asked on what kind of artist will he would like to coach, he said, “I’ve been listening to rock for a long time but I also listen to other genres from rock to pop to folk to everything. I want someone who is open to all kinds of music; someone who is willing to listen and willing to learn.”