I prefer Panentheism over Monotheism.
I don't see a conflict between them. Panentheism literally means "all is in God". From Greek, pan=all, en=in, theos=God. I believe there is only one God (Krishna/Vishnu) and all is in Him as well as He transcends all... immanent and transcendant.
"By Me, in My unmanifested form, this entire universe is pervaded. All beings are in Me, but I am not in them." Bhagavad Gita 9.4 *
(* He is the source of all, yet nothing is the source of Him.)
"Neither the hosts of demigods nor the great sages know My origin or opulences, for, in every respect, I am the source of the demigods and sages." 10.2
"I am the source of all spiritual and material worlds. Everything emanates from Me. The wise who perfectly know this engage in My devotional service and worship Me with all their hearts." 10.8
"But what need is there, Arjuna, for all this detailed knowledge? With a single fragment of Myself I pervade and support this entire universe." 10.42