Expanded Summon Monster Feat and Summoners

[MistoFTW]

Does the feat Expanded Summon Monster work with the Summoner Class's Summon Monster spell like ability? Or if I took the feat, would it only work if I cast Summoner Monster with a spell slot?

[Scrapper]

Unless a feat states it alters a unique ability, in this case, it should only affect spell slots, but is GM's final call.

[David knott 242]

The feat makes no mention of spell slots.

Since a summoner potentially has all Summon Monster spells as spell-like abilities as well as actual spells (for 6 of them), this feat should work just fine for either the spell-like ability or the actual spell.

[James Risner]

David knott 242 wrote:

this feat should work just fine for either the spell-like ability or the actual spell.

+1 my view as a GM.

Somethings that might touch on this:

• Channel feats work no matter what your ability giving you channel is called.
  
• Spell Like Abilities work a lot like casting a spell and at one point used to count as spell casting prerequisites.

@MistoFTW, ask your GM what their view is.

[Azothath]

Expanded Summon Monster(general feat):

Feats >General Feats >
Expanded Summon Monster

You can summon allies beyond the reach of most conjurers.

Prerequisite(s): Ability to cast a summon monster spell.

Benefit(s): For each spell level 1–9, select two creatures from the list below. You then add these creatures to the summon monster table of the same level, allowing you to summon them with the appropriate summon monster spell.

Once made, these choices can’t be changed.

Special: You can take this feat multiple times. Each time you do, you can select two more monsters from the table below to add to the summon monster table of the same level.
1st Level

Antelope* (herd animal)
Baboon* (primate)
Badger*
Great horned owl*
Kangaroo* (marsupial)
Snapping turtle*
Stingray*
Thylacine* (marsupial)
Trumpeter swan*
Vulture*

2nd Level

Camel* (herd animal)
Compsognathus* (dinosaur)
Dimorphodon* (dinosaur)
Gar*
Giant gecko* (lizard)
Giant tortoise*
Giant weasel*
Manta ray*
Ram* (herd animal)
Stag* (herd animal)

3rd Level
...

* This creature is summoned with the celestial template if you are good and the fiendish template if you are evil. If you are neutral, you can choose which template to apply to the creature.

This summoned creature has an alignment that matches yours, regardless of its usual alignment. Summoning this creature makes the summoning spell’s type match your alignment.

so long as it's a Summon Monster spell (cast, spell-like ability, or supernatural ability) by name you are good to go.
I agree that your home GM should agree with that interpretation and should approve your monster choices. He may include more choices.