From a Jain point of view, this is not ideal.

An event that is meant to promote vegetarian living, ahimsa, and purity should not be closely connected with sponsors whose business promotes:

• Alcohol — which increases intoxication, negligence, and harm.
• Mixed food / non-vegetarian restaurants — which are connected with himsa.

In Jain ethics, this can create opposition between your message and your support system. Even if your event itself is vegetarian, taking sponsorship from such businesses may still be seen as indirect support of adharma.

Jain-guided view

It is better to:

• accept sponsorship only from sattvic, vegetarian, and non-violent businesses,
• keep your event’s purpose pure and consistent,
• avoid anything that may confuse people or weaken the spirit of ahimsa and satya.

If you must take such sponsorship

Then, from a practical standpoint, you should:

• clearly separate their branding from the vegetarian message,
• avoid promoting their products at the event,
• and ensure the event does not become a platform for their harmful image.

Simple Jain conclusion

If you want your event to remain truly aligned with Jain values, it is better to avoid alcohol and non-vegetarian sponsors.