Hotel offering party after trendy men ring back (6,4)

'hotel offering party' is the definition.
I know nothing about this answer so I cannot judge whether it can be defined by this definition.

'trendy men ring back' is the wordplay.
'trendy men' becomes 'indoor' (I can't explain this - if you can you should give a lot more credence to this answer).
'ring' becomes 'loop' (a loop is a ring of material).
'back' shows that the letters should be reversed in order.
'loop' backwards is 'pool'.
'indoor'+'pool'='INDOOR POOL'

'after' acts as a link.

Can you help me to learn more?