Bermudagrass is unfortunately difficult to eradicate without resorting to systemic herbicide, often the active ingredient glyphosate. Due to the plant's vigor, more than one application of such an herbicide will probably be needed, and those types of products are capable of damaging nearby desirable plants if the spray contacts their foliage. If needed, sprays can be applied with some type of shield held in place, like scrap pieces of cardboard, to temporarily block drift from the spray from landing on the plant's foliage. (A few scattered drips of herbicide into the soil from sprays running off leaves should not cause problems.) Another option may be to use something to dab/paint the chemical onto the weed foliage that avoids drift reaching nearby plants, such as a disposable sponge.

In the future, if the bermudagrass reappears, to reduce the amount of herbicide needed, the weeds can be physically removed (as much as is possible) and what regrows can be spot-treated with systemic, so there is less overall area to spray/treat. Removing the weed's foliage in this way will also limit its ability to regrow as vigorously, which should make applications more effective. Even so, one or more follow-up applications may still be needed. To avoid herbicide use instead, the bermudagrass would need to be manually removed as thoroughly and promptly (each time it resprouts) as possible. Over time, this will weaken the plant and cause it to die out, since quick and thorough removal prevents the plant from rebuilding root energy reserves for growth, like depleting a battery that isn't able to recharge.

If the landscapers used a contact-type herbicide (one that only kills the above-ground tissues, and is not moved into roots like a systemic herbicide is), then the native plants might regrow in spring. Otherwise, they unfortunately may need to be replaced if the application was a systemic. A licensed pesticide applicator should provide information about exactly what was applied when asked, both the product details (active ingredient(s), or at least product trade name) and a copy of the label information if desired.

For now, any bermudagrass that may be regrowing can be manually removed to weaken it further, and then you'll probably need to wait until spring to see how the plantings (and any remaining pieces of bermudagrass) have fared, since it's getting late to make any additional systemic herbicide applications. You likely don't need to worry about replanting in spring since residue from the application that may have seeped into the soil (depending on how heavily they sprayed) should have degraded or bound tightly to the soil well enough that it won't affect the new plants.

Miri