The pair heard Tyler's story when he was on the trip and decided to give money so Tyler could get his teeth fixed to stop them from going terribly deformed.
Tyler said it was on his bucket list to thank them in person and show them his fixed teeth with his braces on.
"I loved America last time and I really want to thank Jenny and Shelly for what they have done for me. I also want to go back to Disneyland and go to Universal Studios and get some new shoes."
Since the age of 13 months, Tyler has had a pacemaker because of his heart conditions and also has an implanted defibrillator, which jump-starts his heart when it stops.
He also has Long QT Syndrome, a disorder of the electrical activity of the heart, which can result in blackouts and death. and last year was diagnosed with Episodle Dysfunction.
To make things tougher for the young fighter, his mother died when he was just 6.
His grandparents have dedicated their lives to bringing him up, along with his sister, and his grandmother Brenda Holdsworth would go on the trip with him.
Holdsworth said they were blessed to have him in their lives and he had surprised everyone with his love of life and his fight to survive.
"We want him to see Jenny and Shelly before something goes wrong as he might not wake up tomorrow let alone in a month's time. It's not about quality of life it's about what he can fit in it."
Koru Care head nurse Julia Callaghan accompanied Tyler in 2014 and said it was important for him to go again.
She said he came out of his shell and got more out of it than other children there.
"He did every ride at the theme park and there was no holding him back, he really gave everything a go and took everything in his stride. It was amazing for us to watch."
Acting Hastings mayor Sandra Hazlehurst was right behind the cause and hoped to raise the money to get him to America through a mufti day or something similar.
"I met with Tyler and he is such neat young man who deserves this trip so we are going to get together and see how we can raise the funds."
To help get Tyler and Holdsworth to the States people can donate via his Givealittle page: givealittle.co.nz/cause/tylersbucketlist.