Iranian friendship with India was a necessity of the times, the momentum build during sanctions is what carrying things through with deals like Chabahar and Indian investments in their infrastructures.Iran usually marches to the " Tune of a different Drummer ".
But on the surface, its long term National Interest lie with Russia-China-Pakistan block.
Even with good relations with India, Iran would find it extremely difficult to join a Block with Israel and the US and vice versa.
So in all likelihood it would be Russia, China, Iran and Pakistan as a major Block, especially once IRAN officially signs up for CPEC initiative.
Things are in a state of flux right now, remains to be seen if democrats win the election or not. If US - Israel relationships cool down enough then I expect Iran will be more amenable to western bloc but there is a very little chance of that.
I think you are right, Iran would be more comfortable with Russia and China without the dependence on self-righteous and unpredictable US Foreign Policy.
Broadly speaking I see two major power blocs
1. US, Europe, Japan, Israel, Oceania,
2. China, North Korea and Russia and Central Asia Region
Rest of the countries are in somewhat in state of play right now would not commit fully to any bloc.
For all purposes Europe and US bloc are one for now which gives them overwhelming influence but as Europe becomes more independent which they will given enough time and China's rise we will see future power grouping as follows:
1. US, Japan, Oceania and Israel
2. China, North Korea, Pakistan, Central Asia Region and Russia
This would be a very interesting state of play. where influence will adequately balanced.
To prevent this US is fast seeking rapprochement with India
Add India to US bloc in future and and you will see again US gaining primacy.
Now coming to Iran - It will never join US bloc but would remain oscillate between neutral and pro- China and Russia depending on which way the wind is blowing.
Based on rudimentary game theory application to current state of affairs.